Index

@ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

@

A

• access control
  • discretionary
  • mandatory
  • password encryption
  • privileges
• access paths
  • defined
  • list of
  • optimization
• ADMIN OPTION [2]
• AFTER triggers
  • defined
  • when fired
• ALERT files
• ALL_ views
• ALL_LABELS view
• ALL_UPDATABLE_COLUMNS view
• ALTER command
• ALTER TABLE ... DEALLOCATE UNUSED
• ANALYZE command
  • creating histograms
  • shared pool and
• anonymous PL/SQL blocks
  • about
  • vs. stored procedures
• ANSI SQL standard
  • datatypes of
  • Oracle certification
• ANSI/ISO SQL standard
  • data concurrency
  • isolation levels
• applications
  • application triggers vs. database triggers
  • calling packages
  • calling procedures
  • can find constraint violations
  • data dictionary references
  • database access through
  • database links and
  • dependencies of [2]
  • discrete transactions
  • enhancing security with [2]
  • network communication and
  • object dependencies and
  • procedures and
  • program interface and
  • roles and
  • sharing code
  • transaction termination and
• ARCH
• architecture
  • client/server
  • of Oracle
• archived redo log
• ARCHIVELOG mode
  • archiver process (ARCH) and
  • defined
  • overview
  • partial backups and
  • partial database backups
  • when full backups needed in
• archiver process (ARCH)
  • archiving online redo log files
  • automatic archiving
  • defined
  • described
• archiving, defined
• AUDIT command, locks
• audit trail
• auditing
  • audit options
  • audit records
  • audit trail
  • audit trail records
  • by access
    • mandated for
  • by session
    • prohibited with
  • data dictionary used for
  • DDL statements
  • described
  • distributed databases and
  • DML statements
  • examples of
  • matching database and OS usernames
  • object [2]
  • operating system audit trails
  • OS audit trail
  • overview of
  • privilege use [2]
  • range of focus [2]
  • security and
  • statement [2]
  • successful executions
  • transaction independence
  • types of
  • unsuccessful executions
  • user
  • when options take effect
• authentication
  • described
  • network
  • operating system
  • Oracle

  B

• B*-tree indexes
• back-ends
• background processes [2]
  • creation of
  • defined
  • described
  • diagrammed
  • trace files for
• backups
  • consistent
  • control files
  • datafiles
  • for read-only tablespaces
  • full [2]
  • fuzzy
  • inconsistent
  • online
  • overview of [2]
  • partial [2]
  • types of
  • using Export to supplement
• base tables
• BEFORE triggers
  • defined
  • when fired
• blocking transactions
• blocks
  • anonymous
• branch blocks
• buffer cache, writing of
• buffers, database
• business rules
  • enforcing in application code
  • enforcing using stored procedures
  • enforcing with constraints [2] [3]
    • advantages of
  • enforcing with triggers [2]

  C

• caches
  • buffer cache
  • cache hit
  • cache miss
  • data dictionary [2]
    • location of
  • database buffer [2]
  • dictionary
  • library
  • statistics on
  • writing of buffers
• call interface
• cannot serialize access
• cartesian products
• CASCADE actions, DELETE statements and
• chaining of rows [2] [3]
• CHAR datatype
  • blank-padded comparison semantics
  • defined
  • when to use
• character sets, for various languages
• Check constraints
  • defined
  • in partition views
  • subqueries prohibited in
• checkpoint process (CKPT)
  • defined
  • during checkpoints
  • enabling and disabling
  • if not present
• checkpoints
  • after a time interval
  • at log switches
  • checkpoint process
  • control files and
  • database
  • datafile
  • DBWR process
  • during online backups
  • events during
  • fast
  • forcing
  • log writer process performing [2]
  • normal
  • online redo log files and
  • overview of
  • Parallel Server and
  • performance effect of
  • process performing (CKPT)
  • shutting down an instance and
  • signal DBWR process
  • statistics on
  • taking a tablespace offline and
  • types of
  • when checkpoints occur
• child tables
• CKPT
• client/server architectures
  • diagrammed
  • direct and indirect connections
  • distributed databases and
  • distributed processing in
  • overview of [2]
• clients
  • client/server architecture
  • defined
• cluster keys
• clusters
  • choosing data to cluster
  • defined
  • dictionary locks and
  • hash
    • allocation of space for
    • collision resolution
    • contrasted with index
    • root blocks
    • scans of
    • storage of
  • how stored
  • index
    • contrasted with hash
  • indexes and
  • joins and
  • keys [2]
    • affect indexing of nulls
  • overview of
  • performance considerations of
  • ROWIDs and
  • scans of
  • setting parameters of
  • storage format of
  • storage parameters of
• columns
  • correlation names
  • default values for
  • defined
  • described
  • integrity constraints and [2]
  • maximum in concatenated indexes
  • maximum in view or table
  • order of
  • prohibiting nulls in
  • USER pseudo-column
• COMMIT command, two-phase commit and
• committing transactions
  • defined
  • fast commit
  • group commits
  • implementation
  • overview
  • writing the redo log buffer and
• communication protocols
• compatibility
• compiled triggers
• composite indexes [2]
• compression, of free space in data blocks
• concatenated indexes [2]
• concurrency
  • defined
  • described
  • enforced with locks
  • limits on
    • per user
  • manual locks and
  • networks and
  • restrictions on
  • transactions and
• configuration, of a database
• CONNECT INTERNAL
• CONNECT role
• connectibility [2]
• connections
  • defined
  • listener process and
  • restricting
  • sessions contrasted with
  • with administrator privileges
• consistency of data
• consistent backups [2]
• constants, in stored procedures
• constraints
  • alternatives to
  • applications can find violations
  • Check
  • composite UNIQE keys
  • default values and
  • defined
  • disabling temporarily
  • effect on performance
  • enforced with indexes
  • FOREIGN KEY [2]
  • mechanisms of enforcement
  • NOT NULL
  • overview
  • PRIMARY KEY [2]
  • prohibited in views
  • referential
    • self-referencing
  • triggers cannot violate
  • triggers contrasted with
  • types listed [2]
  • UNIQUE key [2]
  • what happens when violated
  • when evaluated [2]
  • when triggers mandated instead
• contention
  • deadlocks
  • for rollback segments
  • lock escalation does not occur
• control files
  • archived redo log information in
  • backing up
  • changes recorded
  • checkpoints and
  • contents
  • defined
  • during incomplete recovery
  • how specified
  • log sequence numbers and [2]
  • media recovery and
  • multiplexed [2]
  • overview
  • physical database structure
  • recovery and
  • used in mounting
  • using backups of in recovery
• correlation names, triggers use of
• cost-based optimization
• CPU time limit
• CREATE PACKAGE command, locks
• CREATE PROCEDURE command, locks
• CREATE SYNONYM command, locks
• CREATE TABLE command
  • locks
  • parallel query option
• CREATE TRIGGER command, locks
• CREATE VIEW command, locks
• cross joins
• cursors
  • defined
  • maximum number of
  • object dependencies and
  • opening
  • overview of
  • private SQL areas and [2]
  • recursive
  • recursive SQL and
  • stored procedures and

  D

• data access
• data blocks
  • allocating for extents
  • cached in memory
  • clustered
  • coalescing free
  • controlling free space in
  • format
  • free lists and
  • hash keys and
  • header's row directory
  • how rows stored in
  • overview
  • read-only transactions and
  • shared in clusters
  • shown in ROWIDs
  • space available for inserted rows
  • stored in the buffer cache
  • writing to disk
• Data Definition Language (DDL)
  • auditing
  • defined
  • described
  • locks
• data dictionary
  • access to
  • adding objects to
  • ALL prefixed views
  • audit trail (SYS.AUD$)
  • cache
    • location of
  • content of
  • DBA prefixed views
  • defined
  • dependencies tracked by
  • DUAL table
  • dynamic performance tables
  • locks
  • overview of
  • owner of
  • prefixes to views of
  • public synonyms for
  • row cache and
  • structure of
  • updates of
  • USER prefixed views
  • uses of
  • views used in optimization
• data locks
  • conversion
  • duration of
  • escalation
• Data Manipulation Language (DML)
  • auditing
  • defined
  • described
  • locks acquired by
  • privileges controlling
  • triggers' use of
• Data manipulation statements (DML), allowed in distributed transactions
• data models
• data segments [2] [3]
• data
  • access to
    • control of
    • security domains
  • access
• database administrators (DBA's)
  • authentication
  • connecting with administrator privileges
  • data dictionary views of
  • password files
  • responsibilities for backup
• database buffers
  • after committing transactions
  • buffer cache [2]
  • checkpoints and
  • clean
  • committing transactions
  • defined
  • dirty [2]
  • free
  • pinned
  • size of cache
  • writing of
• database links
  • defined
  • overview of
• database management systems (DBMS's), principles
• database management systems (DBMSs)
  • Oracle Server
• database triggers
• database writer process (DBWR)
  • checkpoints and
  • checkpoints signal
  • defined
  • least recently used algorithm (LRU)
  • multiple
  • overview of
  • time-outs
  • when active
  • writing to disk at checkpoints
• databases
  • access control
  • accessing non-Oracle
  • backing up [2]
  • closing
    • aborting the instance
  • configuring
  • contain schemas
  • defined
  • dismounting
  • distributed
    • local
    • nodes of
    • overview of [2]
    • remote
    • site autonomy of
    • statement optimization on
    • two-phase commit
  • global database names
  • implementation of
  • logical structure of
  • logical structures (objects) in
  • modes of
    • NOARCHIVELOG
  • mounting
  • open and closed
  • opening
    • acquiring rollback segments and
  • physical structure [2] [3]
  • physical structure of
  • recovery of [2]
  • scaled
  • shutting down
  • size of
    • how determined
  • standby
  • starting up
    • forced
  • usage of
• data
  • concurrent access to
  • consistency of
    • described
    • examples of lock behavior
    • locks
    • manual locking
    • repeatable reads
    • transaction level
    • underlying principles
  • distributed manipulation of [2]
• datafiles
  • adding to tablespaces
    • cannot if read-only
  • backing up
  • backups
  • contents of
  • in online or offline tablespaces
  • log sequence numbers and
  • named in control files
  • offline during incomplete recovery
  • overview
  • overview of [2]
  • physical database structure
  • read-only
    • recovery
  • recovery of
  • relationship to tablespaces
  • shown in ROWIDs
  • taking offline
• data
  • how stored in tables
  • integrity of [2] [3] [4]
    • Check constraints
    • comparison of enforcement methods
    • enforcing with triggers
    • overview
    • read consistency
    • referential [2]
    • two-phase commit
    • types
  • locks on
  • replicating [2]
  • storage of in clusters
• datatypes
  • ANSI
  • character
  • CHAR
  • choosing a character datatype
  • conversions of
    • Oracle to non-Oracle types [2]
  • DB2
  • how they relate to tables
  • list of available
  • LONG
  • numeric
  • of columns
  • SQL/DS
  • VARCHAR2
• DATE datatype
  • arithmetic with
  • changing default format of
  • described
  • Julian dates
• DB_BLOCK_BUFFERS parameter
  • buffer cache and
  • system global area size and
• DB_BLOCK_LRU_LATCHES parameter
• DB_BLOCK_SIZE parameter, System Global Area size and
• DB_FILE_MULTIBLOCK_READ_COUNT parameter
• DB_FILES parameter
• DB_WRITERS
• DBA role
• DBA_ views
• DBA_SYNONYMS.SQL script, using
• DBA_UPDATABLE_COLUMNS view
• DBMS
• DBMS_SQL package
• DBWR
• DDL
• deadlocks
  • artificial
  • avoiding
  • defined
  • detection of
  • distributed transactions and
• deallocating extents
• dedicated servers
  • defined
  • examples of use
  • multi-threaded servers contrasted with
• default values [2]
  • constraints effect on [2]
• delete cascade
• DELETE command
  • foreign key references and
  • freeing space in data blocks
• delete restrict
• dependencies, between schema objects [2]
  • local
  • non-existent referenced objects and
  • on non-existence of other objects
  • Oracle Forms triggers and
  • privileges and
  • remote objects and
  • shared pool and
• dependent tables
• dictionary cache locks
• different row-writers block writers
• dirty buffer
• dirty read [2]
• dirty write
• disaster recovery
• discrete transaction management, summary
• discretionary access control [2]
• disk failures
• disk space
  • controlling allocation for tables
  • datafiles used to allocate [2]
• dispatcher processes (Dnnn)
  • defined
  • described
  • limiting SGA space per session
  • listener process and
  • network protocols and
  • prevent startup and shutdown
  • response queue and
  • user processes connect through SQL*Net
• distributed databases [2]
  • auditing and
  • client/server architectures and
  • database links
  • deadlocks and
  • dependent objects and
  • diagrammed
  • distributed queries
  • distributed updates
  • global object names
  • heterogeneous
  • nodes of
  • overview of [2]
  • performance and
  • procedure dependencies in
  • recoverer process (RECO) and
  • referential integrity and
  • remote queries and updates
  • server can also be client in
  • site autonomy of
  • snapshot refresh process (SNPn)
  • SQL*Net
  • statement optimization on
  • table replication
  • transparency of
  • two-phase commit
• distributed processing environment
  • client/server architecture in
  • described
• distributed transactions
  • defined
  • in a heterogeneous environment
  • involving non-Oracle databases
• DISTRIBUTED_TRANSACTIONS parameter
• DML
• Dnnn [2]
• drivers
• DUAL table
• dynamic performance tables (V$ tables)
• dynamic SQL, DBMS_SQL package

  E

• embedded SQL statements [2]
• equijoins, defined
• errors
  • during PL/SQL compilation
  • internal
• exceptions
  • during trigger execution
  • raising
  • stored procedures and
• exclusive locks
  • DDL locks
  • defined
  • row locks (TX)
  • RX locks
  • table locks (TM)
• exclusive mode [2]
• execution plans
  • execution sequence of
  • location of
  • overview of
  • viewing
• EXP_FULL_DATABASE role
• explicit locking [2]
• Export utility, use in backups
• extents
  • allocating data blocks for
  • allocation to rollback segments
    • at segment creation
  • allocation, how performed
  • as collections of data blocks
  • deallocation from rollback segments
  • deallocation
  • defined
  • dropping rollback segments and
  • in rollback segments
  • incremental
  • initial
  • overview of
  • parallel query option

  F

• failures
  • archiving redo log files
  • database buffers and
  • database instance
  • described
  • during checkpoints
  • instance
    • recovery from
  • internal errors
  • media
    • multiplexed online redo logs and
    • recovery from
  • network
  • safeguards provided
  • statement and process
  • types of
  • user error [2]
• fast commit
• fast transaction rollback
• fast warmstart
• file management locks
• files
  • operating system
  • X
• FIPS standard
• flagging of nonstandard features
• FOREIGN KEY constraints
  • changes in parent key values
  • deleting parent table rows and
  • maximum number of columns in
  • nulls and
  • updating parent key tables
• foreign keys
  • defined
  • partially null
  • privilege to use parent key
• free lists
• free space (section of data blocks)
• front-ends
• full backups
• full table scans
• functions
  • contrasted with procedures
  • described
  • hash
  • in views
  • packages can contain
  • privileges for
  • procedures contrasted with
• fuzzy backups [2]
• fuzzy reads

  G

• gateways
• global object names
• GRANT ANY PRIVILEGE system privilege
• GRANT command, locks
• granting, privileges and roles
• group commits

  H

• handles, for SQL statements
• hash clusters [2]
  • overview of
• HASHKEYS parameter
• headers
  • of data blocks
  • of row pieces [2]
• HIGH_VALUE column, of USER_TAB_COLUMNS view
• histograms

  I

• IMP_FULL_DATABASE role
• Import utility, use in recovery
• in-doubt transactions
• inconsistent, backups
• index segments [2]
• indexes
  • B*-tree structure of
  • branch blocks
  • cluster
    • contrasted with table
    • dropping
  • composite
  • concatenated
  • described
  • internal structure of
  • keys and
  • leaf blocks
  • location of
  • LONG RAW datatypes prohibit
  • non-unique
  • nulls and
  • overview of
  • parallel query option
  • performance and
  • PRIMARY KEY constraints enforced with
  • ROWIDs and
  • scans of
  • storage format of
  • unique
  • UNIQUE key constraints enforced with
  • when used with views
• INIT.ORA files
• initialization parameters, DB_BLOCK_LRU_LATCHES
• INSERT command
  • foreign key references and
  • free lists and
• instance recovery
• instances
  • acquire rollback segments
  • associating with databases [2]
  • configuration of
  • defined
  • described
  • diagrammed
  • failure in [2]
  • memory structures of
  • multi-process
  • multiple-process
  • overview of
  • recovery of
    • procedure
  • restricted mode
  • sharing databases [2]
  • shutting down [2]
  • single-process
  • starting
  • virtual memory
• integrity constraints
• integrity rules
  • in a relational database
• INTERNAL
• internal errors, tracked in trace files
• INTERNAL, audit records not generated by
• INVALID status [2]
• IS NULL predicate
• ISO SQL standard [2]
• isolation levels
  • choosing
  • comparing
  • read committed
  • serializable
  • setting
• ITSEC security standard

  J

• jobs
• join views
• joins
  • cartesian products
  • clusters and
  • cross
  • defined
  • encapsulated in views [2]
  • equijoins
  • nonequijoins
  • outer

  K

• key values [2]
• keys, cluster [2] [3]
  • foreign
  • hash
  • in constraints
  • indexes and
  • maximum storage for values
  • parent
  • primary
  • referenced [2]
  • unique [2]
    • defined
    • how enforced

  L

• latches
  • defined
  • described
  • LRU
• LCKn
• leaf blocks
• least recently used algorithm (LRU)
  • database buffers and
  • latches
• LGWR
• library caches
  • memory allocation for
  • size of
• licensing
  • concurrent usage
  • named user
  • viewing current limits
• listener processes
• local databases [2]
• location transparency [2]
• lock processes (LCKn) [2] [3]
• locks
  • after committing transactions
  • automatic [2] [3]
  • conversion
  • data [2]
    • duration of
  • deadlocks [2]
    • avoiding
  • dictionary [2]
  • dictionary cache
  • dictionary
    • duration of
    • exclusive
    • share
  • distributed
  • DML acquired
    • diagrammed
  • escalation
  • escalation does not occur
  • exclusive
  • exclusive table locks (X)
  • file management locks
  • how Oracle uses
  • internal [2]
  • latches and
  • log management locks
  • manual [2]
    • examples of behavior
  • Oracle Lock Management Services
  • overview of [2]
  • parallel cache management (PCM)
  • parse
  • rollback segment
  • row (TX)
  • row exclusive locks (RX)
  • row share table locks (RS)
  • share
  • share row exclusive locks (SRX)
  • share table locks (S)
  • share-sub-exclusive locks (SSX)
  • sub-exclusive table locks (SX)
  • sub-share table locks (SS)
  • table (TM)
  • table
  • tablespace
  • types
  • types of
• log management locks
• log sequence numbers [2]
  • after datafile recovery
  • control files and [2]
  • datafiles and
  • during recovery
  • multiplexed redo logs and
  • resetting to 1
• log switches
  • described
  • log sequence numbers
  • mirrored redo log files and
• log writer process (LGWR)
  • archiver process (ARCH) and
  • checkpoint process (CKPT) and
  • defined
  • group commits
  • manual archiving and
  • multiplexed redo log files and
  • online redo logs available for use
  • overview
  • redo log buffers and
  • system change numbers
  • trace files and
  • writing to online redo log files [2]
• LOG_BUFFER parameter
  • defined
  • System Global Area size and
• LOG_CHECKPOINT_INTERVAL parameter
• LOG_CHECKPOINT_TIMEOUT parameter
• LOG_FILES parameter
• logical blocks
• logical database structure
• logical reads limit
• logical structures
• LONG datatype
  • automatically the last column
  • defined
  • restrictions on
  • storage of
• LONG RAW datatype
  • defined
  • indexing prohibited on
  • restrictions on
  • similarity to LONG datatype
• LOW_VALUE column, of USER_TAB_COLUMNS view
• LRU

  M

• MAC
• mandatory access control
• manual locking
• match
  • full
  • none
  • partial
• media failure, described
• memory
  • content of
  • cursors (statement handles)
  • library cache
  • overview of structures in
  • procedures can reduce usage
  • processes use of
  • sessions
  • SGA size and
  • shared SQL areas
    • allocation for
  • software code areas
  • sort areas
  • SQL statements
  • structures in
  • System Global Area (SGA) allocation in
  • system global area (SGA)
  • virtual
• mirroring
• MLSLABEL datatype
• modes
  • ARCHIVELOG
  • exclusive
  • NOARCHIVELOG
  • parallel
  • single-task
  • table lock
  • two-task
• monitoring user actions
• MTS_MAXSERVERS parameter, artificial deadlocks and
• multi-threaded server
  • artificial deadlocks in
  • dedicated server contrasted with
  • defined
  • described
  • dispatcher processes
  • example of use
  • memory allocation and
  • processes needed for
  • restricted operations in
• multi-threaded servers [2]
• multi-threaded server, SQL*Net V2 requirement
• multi-user environments [2]
• multiblock writes
• multiple-process systems (multi-user systems) [2]
• multiplexing, control files [2]
  • recovery and
  • redo log files [2] [3]
• multiverison consistency model
• multiversion concurrency control

  N

• name resolution, in distributed databases
• named user licensing
• National Language Support (NLS)
  • character sets for
  • Check constraints and
  • clients and servers may diverge
  • defined
  • views and
• networks
  • client/server architecture use of
  • communication protocols of
  • communications software for
  • dispatcher processes and
    • protocols, use of
  • distributed databases' use of
  • drivers
  • failures of
  • independence from in distributed databases
  • listener processes of
  • network authentication service
  • SQL*Net
  • two-task mode and [2]
  • using Oracle on [2]
• NLS
• NLS_DATE_FORMAT parameter
• NOARCHIVELOG mode
  • defined
  • full backups required for recovery in
  • overview
• NOAUDIT command, locks
• nodes, of distributed databases
• non-repeatable reads [2]
• non-unique indexes
• nonequijoins, defined
• NOT NULL constraints
  • defined
  • implied in PRIMARY KEY constraints
  • UNIQUE keys and
• nulls
  • as default values
  • column order and
  • converting to values
  • defined
  • equality of in UNIQUE key constraints
  • foreign keys and [2]
  • how stored
  • indexes and
  • prohibited in primary keys
  • prohibiting
  • UNIQUE key constraints and
  • unknown in comparisons
• NUM_DISTINCT column, USER_TAB_COLUMNS view
• NUM_ROWS column, USER_TABLES view
• NUMBER datatype
  • internal format of
  • rounding
• NVL function

  O

• object privileges
• objects
  • auditing access to
  • dependencies of
  • in a database schema
• OCI
• offline backups
  • consistent [2]
  • datafiles
  • full
  • fuzzy data and
• offline redo log files
• online backups
  • datafiles
• online redo log
• OPEN_CURSORS parameter
  • defined
  • managing private SQL areas
• OPEN_LINKS parameter
• operating systems
  • authentication by
  • block size
  • privileges required for CONNECT INTERNAL
  • roles and
• operating-system communications software
• operations, in a relational database
• OPTIMAL storage parameter [2]
• optimization
  • cost-based
    • choosing an access path
    • examples of
    • remote databases and
  • described
  • rule-based
    • choosing an access path
    • examples of
  • selectivity of queries and
• Oracle blocks
• Oracle call interface (OCI)
• Oracle code
• Oracle Forms
  • application triggers contrasted with database triggers
  • object dependencies and
  • Version 3
• Oracle Parallel Server, isolation levels
• Oracle program interface (OPI) [2]
• Oracle Server
• Oracle, adherence to industry standards [2] [3]
  • architecture [2]
  • client/server architecture of
  • compatibility
  • configurations of
  • connectability of
  • connectibility
  • data access
  • examples of operations [2]
  • features [2]
  • instances
  • licensing of
  • Oracle Server
  • Parallel Server option
  • portability
  • processes of [2]
  • recovery features of
  • scalability of
  • single-process Oracle
  • SNMP support
  • Trusted
  • using on networks [2]
• Orange Book security standard
• OS_AUTHENT_PREFIX parameter, operating system authentication and
• outer joins, defined

  P

• packages
  • as program units
  • auditing
  • bodies of [2]
  • cached in the shared pool
  • compilation and entry into database of
  • defined
  • dependency tracking in
  • encapsulate procedures
  • errors in
  • examples of [2] [3]
  • execution of
  • execution steps of
  • for locking
  • introduced
  • overview of
  • performance effect of
  • privilege to execute
  • privileges
    • executing
  • public and private data and procedures
  • session state and
  • shared SQL areas and
  • specifications of [2]
  • stand-alone procedures contrasted with
  • uses of
  • validation status
  • verifying user access
• pages
• parallel mode
• parallel query option, space management
• parallel recovery [2]
• Parallel Server
  • checkpoints and
  • concurrency limits and
  • databases and instances
  • distributed locks
  • exclusive mode
  • file and log management locks
  • introduced
  • lock processes
  • modes of
  • mounting a database using
  • named user licensing and
  • PCM locks
  • shared mode
  • system change numbers
  • system monitor process and
  • threads of online redo log
• parameter files
  • described
  • example of
  • introduced
• parameters
  • initialization
  • national language support
  • ROLLBACK_SEGMENTS
  • SORT_AREA_SIZE
  • TRANSACTIONS
  • TRANSACTIONS_PER_ROLLBACK_SEGMENT
• parent tables
• parse locks
• parse trees
  • construction of
  • location of
  • of procedures
• parsing
  • parse calls
  • performed
• partial backups [2]
• partition views
• passwords
  • connecting without
  • database user authentication and
  • encryption
  • password files
  • used in roles
• pcode
• PCTFREE storage parameter
  • how it works
  • PCTUSED and
• PCTUSED storage parameter
  • how it works
  • PCTFREE and
• performance, checkpoints effect [2]
  • clusters and
  • constraint effects on
  • distributed databases and
  • group commits
  • packages and
  • parallel recovery and
  • procedures and
  • procedures effect on
  • resource limits and
  • SGA size and
  • structures that improve
  • viewing execution plans
• persistent areas
• PGA
• phantom reads
• phantoms
• physical database structure
• PL/SQL
  • and database triggers
  • anonymous blocks [2]
  • auditing of statements within
  • blocks
  • engine
  • exception handling
  • executing
  • introduced
  • language constructs
  • overview
  • overview of [2]
  • parse locks
  • PL/SQL blocks
  • PL/SQL engine
  • procedures and
  • program units
  • stored procedures
  • trigger actions
• PMON
• portability
• prefixes, data dictionary view
• PRIMARY KEY constraints
  • described
  • indexes used to enforce
    • name of
  • maximum number of columns in
  • NOT NULL constraints implicit in
• primary keys
  • described
  • integrity constraints and
• private SQL areas
  • cursors and
  • described
  • how managed
  • persistent areas
  • runtime areas
• private, rollback segments
• privileges
  • auditing the use of
  • auditing use of
  • granting [2]
    • examples of [2]
    • to roles
  • grouping into roles
  • object
    • granting and revoking
    • overview of
  • overview of [2]
  • procedures
    • altering
    • creating
    • divided by construct
    • executed under owner's
    • executing
  • revoked
  • roles and
  • roles
  • system
    • granting
    • overview of
  • to start up or shut down a database
  • trigger
  • views
    • creating
• procedures
  • anonymous PL/SQL blocks contrasted with
  • applications and
  • applications for
  • auditing
  • cached in the shared pool
  • compilation and entry into database of
  • contrasted with functions
  • cursors and
  • dependency tracking in [2]
  • described
  • design and use of
  • encapsulating in packages
  • errors in
  • examples of [2]
  • execution of
  • execution steps of
  • functions contrasted with
  • introduced
  • INVALID status [2]
  • memory usage and
  • packages can contain
  • parse trees produced for
  • performance effect of [2]
  • PL/SQL and
  • prerequisites for compilation of
  • privileges on
    • executing
    • executing any
  • privileges
    • to execute
  • pseudocode (P code)
  • security and
  • security enhanced by
  • shared SQL areas and
  • stand-alone
  • stored procedures
  • triggers contrasted with
  • VALID status
  • validation status
  • verifying user access
• Process Global Area (PGA)
  • allocation of
• process monitor process (PMON)
  • cleans up timed-out sessions
  • described [2]
  • detects failures
• processes, archiver (ARCH) [2]
  • background [2]
    • diagrammed
  • checkpoint (CKPT) [2]
  • checkpoints and
  • database writer (DBWR) [2]
  • dedicated server
  • described
  • dispatcher (Dnnn) [2]
  • distributed transaction resolution and
  • during recovery
  • failure in
  • listener
    • shared servers and
  • lock (LCKn) [2]
  • log writer (LGWR) [2]
  • multi-threaded server requires
  • multi-threaded
    • client requests and
  • multiple-process Oracle
  • Oracle [2]
  • overview of
  • process monitor (PMON) [2]
  • recoverer (RECO) [2]
    • and in-doubt transactions
  • server [2] [3]
    • dedicated
    • shared
  • shadow
  • shared server
  • single-process Oracle
  • snapshot refresh (SNPn)
  • structure
  • system monitor (SMON) [2]
  • trace files for
  • user [2]
    • allocate PGAs
    • recovery from failure of
    • sharing server processes
• processing, distributed
• profiles
  • overview of
  • when to use
• Program Global Area (PGA)
  • contents of
  • defined
  • multi-threaded servers
  • non-shared and writable
  • session information and
  • size of
• program interface
  • Oracle side (OPI)
  • overview of [2]
  • single-task mode in
  • structure of
  • two-task mode in
  • user side (UPI)
• program units
  • overview of
  • PL/SQL and
  • prerequisites for compilation of
• pseudocode (P code) for procedures
• pseudocolumns
  • ROWID
• PUBLIC user group
  • difference from public variables
• public, rollback segments

  Q

• queries
  • and partition views
  • compound
  • default locking of
  • defined
  • distributed
  • distributed or remote
  • in DML
  • location transparency and
  • merged with view queries
  • non-Oracle databases and
  • phases of
  • read consistency of
  • selectivity of
  • stored
  • stored as views [2]
  • triggers' use of
• query servers, extent allocation
• quotas
  • revoking tablespace access and
  • setting to zero
  • tablespace [2]
  • tablespaces

  R

• RAW datatype
• RDBMS, processes of
• read committed
  • isolation
  • vs. serializable
• read consistency
  • defined
  • multiversion consistency model
  • rollback segments and
  • snapshot too old message
  • transaction level
  • transactions
  • triggers and
• read snapshot time
• read uncommitted
• read-only tablespaces
  • backing up
  • described
  • restrictions on
• read-only transactions
• readers block writers
• reads
  • data block
  • dirty
  • repeatable
• RECO
• recoverer process (RECO)
  • and in-doubt transactions
  • overview of
• recovery
  • basic steps
  • closed database
  • control files during incomplete
  • database buffers and
  • database
  • diagrammed
  • distributed processing in
  • features of
  • full backups and
  • in parallel
  • incomplete
    • requirements of
  • instance
    • automatic
    • required after abort
    • system monitor process (SMON) and
  • media
    • backup control files used
    • backup datafiles and
    • cancel-based
    • complete
    • control files and
    • datafile
    • disabled
    • dispatcher processes and
    • enabled
    • examples of
    • incomplete [2]
    • log sequence numbers during
    • mechanisms involved
    • NOARCHIVELOG mode
    • open database-offline tablespace
    • overview of
    • read-only tablespaces and
    • redo log files applied
    • rolling back
    • time-based
  • of distributed transactions
  • overview of
  • process [2]
  • recommendations for
  • requirements of
  • rolling back during
  • rolling forward and
  • statement failure
  • steps of
  • structures used in [2]
• recursive SQL, cursors and
• redo entries, content of
• redo log buffers
  • circularity
  • committing a transaction
  • log writer process and
  • overview
  • size of
  • writing
  • writing of
• redo log files [2]
  • "fuzzy" data in backups and
  • active (current)
  • applied during media recovery
  • archived
    • advantages of
    • automatic
    • contents of
    • control files and
    • errors in archiving
    • log switches and
    • manually
    • mechanics of archiving
  • archiver process (ARCH) and
  • available for use
  • buffer management
  • contents of
  • distributed transaction information in
  • files named in control file
  • groups
  • inactive
  • log sequence numbers of
    • uses
  • log switches
  • log writer process [2]
  • members
  • mirrored
    • if all inaccessible
    • if some inaccessible
    • log switches and
  • mode of
  • multiplexed [2]
    • diagrammed
    • purpose of
  • offline
  • online [2]
    • after checkpoint failure
    • loss of
    • recovery use of
    • requirement of two
    • threads of
  • overview of [2]
  • parallel recovery
  • physical database structure
  • recovery and
  • resetting log sequence numbers
  • rollback segments and
  • rolling forward and
  • when temporary segments in
  • written before transaction commit
• referenced, keys [2]
  • objects
  • tables
• REFERENCES privilege, when granted through a role
• referential integrity [2] [3]
  • cascade rule
  • distributed databases and
  • examples of
  • intermediate states and
  • partially null foreign keys
  • PRIMARY KEY constraints
  • restrict rule
  • self-referential constraints [2]
  • set to default rule
  • set to null rule
• refresh, snapshot refresh process
• relational database management systems (RDBMS's), principles [2]
  • SQL and
• relations
• remote databases [2]
• remote transactions
• repeatable reads
• replicating data [2]
• replication option [2]
• reserved words
• resource limits
  • call level
  • connect time per session
  • CPU time limit
  • determining values for
  • idle time per session
  • logical reads limit
  • overview of
  • private SGA space per session
  • session level
  • sessions per user
• RESOURCE role
• response queues [2]
• restricted mode, starting instances in
• REVOKE command, locks
• roles
  • application
  • CONNECT role
  • DBA role
  • DDL statements and
  • dependency management in
  • disabling
  • enabling
  • EXP_FULL_DATABASE
  • functionality [2]
  • granting [2]
    • to other roles
    • users capable of
  • IMP_FULL_DATABASE
  • in applications
  • management using the operating system
  • naming
  • overview of
  • predefined
  • RESOURCE role
  • restrictions on privileges of
  • revoking
    • users capable of
  • schemas do not contain
  • security domains of
  • use of passwords with
  • user
  • uses of
• rollback
• rollback entries [2]
• rollback segments
  • access to
  • acquired during startup
  • allocating new extents for
  • allocation of extents for
  • clashes when acquiring
  • committing transactions and
  • contention for
  • deallocating extents from
  • deferred
  • defined
  • dropping
    • restrictions on
  • how transactions write to
  • in-doubt distributed transactions and
  • invalid
  • locks on
  • media recovery use of
  • moving to the next extent of
  • number of transactions per
  • offline [2]
  • offline tablespaces and
  • online [2]
  • overview of
  • parallel recovery
  • partly available
  • private
  • public
  • read consistency and [2] [3]
  • recovery needed for
  • states of
    • viewing
  • SYSTEM rollback segment
  • transactions and
  • use of in recovery
  • when acquired
  • when used
  • written circularly
• rollback
  • caused by PMON
  • defined
  • described
  • during recovery
• rolling back during recovery [2] [3]
• rolling back transactions [2] [3]
• rolling forward during recovery [2] [3]
• rolling forward, during recovery
• root blocks
• row cache
• row data (section of data block)
• row directories [2] [3]
• ROW LOCKING parameter
• row locking, and serializable transactions
• row pieces
  • headers
  • how identified
• row sources
• row triggers
  • when fired
• row-level locking
• ROWID datatype
• ROWIDs
  • accessing
  • changes in
  • examples of use
  • in non-Oracle databases
  • internal use of
  • of clustered rows
  • retained during migration
  • sorting indexes by
  • table access by
• ROWLABEL pseudocolumn
• rows
  • addresses of
  • chaining across blocks [2]
  • clustered
    • ROWIDs of
  • defined
  • described
  • directories in
  • format of in data blocks
  • headers
  • locking
  • locks on
  • migration between data blocks
  • pieces of
  • row sources
  • ROWIDs used to locate
  • shown in ROWIDs
  • size of
  • storage format of
  • triggers on
  • when ROWID changes
• rule-based optimization
• runtime areas

  S

• same-row writers block writers
• savepoints
  • described
  • overview of
  • rolling back to
• scaling your database
• scans
• schema objects
  • allocated segments
  • auditing
  • creating
  • default tablespace for
  • defined
  • dependencies between
  • dependencies of
    • and views
    • on non-existence of other objects
    • package tracking of
    • procedure tracking of
    • triggers manage
  • dependent on lost privileges
  • distributed database naming conventions for
  • global names
  • in a revoked tablespace
  • information about
  • INVALID status
  • overview of [2]
  • privileges on
    • DDL
  • relationship to datafiles [2]
  • trigger dependencies on
  • VALID status
• schemas
  • associated with users [2]
  • contents of
  • contrasted with tablespaces
  • defined
  • objects in [2]
• SCN
• security
• security domains
  • enabled roles and
  • tablespace quotas
• security
  • application enforcement of
  • auditing [2]
  • auditing user actions
  • data
  • described
  • discretionary
  • discretionary access control
  • domains
  • enforcement mechanisms
  • procedure and package access validation
  • procedures and
  • procedures enhance
  • program interface enforcement of
  • system
  • views and
  • views enhance
• segments
  • allocating extents for
  • allocating
  • data
  • deallocating extents from
  • defined
  • header block
  • index
  • minimum number of extents in
  • overview
  • overview of
  • rollback
  • temporary [2]
    • cleaned up by SMON
    • dropping
    • ignore quotas
    • operations that require
    • tablespace containing
  • used to store schema objects
• selectivity of queries
• sequences [2]
  • auditing
  • independence from tables
  • length of numbers
  • number generation
  • VALID status
• SERIALIZABLE parameter
  • locking
• serializable
  • isolation
  • vs. read committed
• server processes
• servers
  • client/server architecture
  • dedicated
  • dedicated processes
  • dedicated server architectures
  • dedicated
  • defined
  • multi-threaded
  • multi-threaded server architectures
  • multi-threaded
    • processes of
  • processes of
  • shared
• session control statements [2]
• sessions
  • connections contrasted with
  • defined
  • limit on concurrent
    • by license
    • imposed by DBA
  • limits per user
  • package state and
  • resource limits and
  • time limits on
  • when auditing options take effect
• SET TRANSACTION READ ONLY statement [2]
• sets, LRU latches
• share locks
  • DDL locks
  • defined
  • share table locks (S)
• Shared Global Area (SGA)
• shared mode
• shared pool
  • allocation of
  • ANALYZE command and
  • anonymous PL/SQL blocks and
  • compiled PL/SQL code in
  • dependency management and
  • described
  • flushing
  • object dependencies and
  • overview of
  • procedures and
  • row cache and
  • size of
• shared servers
  • cannot CONNECT INTERNAL to
• shared SQL areas
  • ANALYZE command and
  • dependency management and
  • described [2]
  • how managed
  • memory allocation for
  • overview of
  • parse locks and
  • procedures, packages, triggers and
  • size of
• SHARED_POOL_SIZE parameter
  • System Global Area size and
• shutdown
• SHUTDOWN ABORT
• shutdown
  • abnormal
  • checkpoints and
  • deallocation of the SGA
  • described
  • prohibited by dispatcher processes
  • steps
• single-process systems (single-user systems)
• single-task mode
• site autonomy [2] [3]
• SMALL_TABLE_THRESHOLD parameter
• SMON
• snapshot refresh process (SNPn)
• snapshot too old message
• snapshots [2]
  • refreshing
• SNMP support
• SNPn
• software code areas
  • shared by programs and utilities
• sort areas
• sort direct writes feature
• SORT_AREA_RETAINED_SIZE parameter
• SORT_AREA_SIZE parameter [2]
• space management
  • compression of free space
  • extent management
  • parallel query option
  • PCTFREE
  • PCTUSED
  • row chaining
  • segments
• SQL
• SQL areas
  • private
    • persistent
    • runtime
  • shared
• SQL statements
  • audit records of
  • auditing [2]
  • complex
  • dictionary cache locks and
  • distributed databases and
  • distributed
    • optimization of
  • execution plans of
  • failure in
  • in trigger actions
  • number of triggers fired by single
  • optimization of
  • parse locks
  • privileges required for
  • procedural extensions to
  • referencing dependent objects
  • resource limits and
  • successful execution
  • trigger events and
  • triggers fired by
  • triggers on
• SQL*Connect
• SQL*Net
  • applications and
  • client/server systems use of
  • how it works
  • multi-threaded server V2 requirement
  • network independence and
  • overview of [2]
  • program interface and
• SQL*Plus
• SQL92
• SQL_TRACE parameter
• SQL
  • cursors used in
  • Data Definition Language (DDL)
  • embedded in other languages
  • embedded SQL
  • functions
  • overview of [2]
  • parsing of
  • PL/SQL
  • PL/SQL and [2]
  • recursive
    • cursors and
  • reserved words
  • session control statements
  • shared areas
  • shared SQL
  • statement-level rollback
  • statements in
  • statements
  • system control statements
  • transaction control statements
  • transactions
  • transactions and
  • types of statements in [2]
• standards
  • Oracle adherence
  • Oracle adherence with
• standby database
• startup
  • allocation of the SGA
  • described
  • exclusive mode
  • fast warmstart
  • forcing
  • parallel mode
  • prohibited by dispatcher processes
  • recovery during
  • restricted mode
  • steps
• statement triggers
  • described
  • when fired
• statement-level read consistency
• statements
  • auditing the use of
  • handles
  • in SQL
    • types of
• statistics
  • caches
  • checkpoint
  • optimizer use of
• STORAGE clause, using
• storage parameters
  • OPTIMAL (in rollback segments)
  • setting
• storage, datafiles [2]
  • logical structures [2]
  • of hash clusters
  • of index clusters
  • of indexes
  • of nulls
  • of views
  • procedures and packages in the database
  • restricting for users
  • revoking tablespaces and
  • tablespace quotas and
  • triggers [2]
  • user quotas on
• stored functions
• stored procedures
  • SYSTEM tablespace and
• Structured Query Language
• structure
  • of databases
    • logical
• structures
  • databases
  • in a relational database
  • locking
  • logical
  • physical
  • schema objects [2]
• subqueries
  • Check constraints prohibit
  • in remote updates
• survivability
• synonyms
  • constraints indirectly affect
  • described
  • for data dictionary views
  • inherit privileges from object
  • overview of
  • private
  • public
  • uses of
  • VALID status
• SYS username
  • audit records not generated by
  • data dictionary tables owned by
  • security domain of
• SYS.AUD$ view, purging
• SYSDBA privilege
• SYSOPER privilege
• system change numbers (SCN)
  • change-based recovery
  • committed transactions
  • defined
  • read consistency and [2]
  • redo logs
  • when determined [2]
• system control statements [2]
• System Global Area (SGA)
  • allocating
  • contents of [2]
  • data dictionary cache
  • database buffer cache
  • determining size
  • diagram
  • fixed
  • limiting use of in multi-threaded server
  • overview of [2]
  • redo log buffer
  • shared and writable
  • shared pool
  • size of
  • when allocated
• system monitor process (SMON)
  • defined
  • Parallel Server and
• system privileges
  • ADMIN OPTION
  • described
  • granting
  • revoking
• SYSTEM rollback segment
• SYSTEM tablespace [2] [3]
  • online requirement of
  • procedure storage and
• SYSTEM, security domain of

  T

• table directories
• tables
  • affect dependent views
  • auditing
  • base
    • data dictionary use of
    • relationship to views
  • child
  • clustered
  • contain integrity constraints
  • contained in tablespaces
  • controlling space allocation for
  • dependent
  • hash
  • how data is stored in
  • indexes and
  • locks on [2] [3]
  • maximum number of columns in
  • overview of [2]
• tablespaces
  • backups and checkpoints
  • contrasted with schemas
  • default for object creation [2]
  • described
  • during incomplete recovery
  • how specified for tables
  • locks on
  • media recovery and
  • offline
    • and index data
    • not if read-only
    • remain offline on remount
    • what happens to datafiles
  • online
  • online or offline
  • online
    • what happens to datafiles
  • overview of [2]
  • quotas on [2] [3] [4]
    • limited and unlimited
    • no default
  • read-only
    • dropping objects from
    • making tablespaces read-only
    • media recovery and
  • relationship to datafiles
  • revoking access from users
  • size of
  • temporary [2]
    • default for user
  • used for temporary segments
• tables
  • parallel query option
  • parent
  • presented in views
  • privileges on
  • replicating [2]
  • replication
  • snapshots [2]
  • specifying tablespaces for
  • triggers used in
  • VALID status
  • virtual or viewed
• tasks
• temporary segments
  • allocating
  • deallocating extents from
  • dropping
  • ignore quotas
  • operations that require
  • tablespace containing
  • when not in redo log
• temporary tablespaces
• threads
  • online redo log
• three-valued logic (true, false, unknown), produced by nulls
• time-outs
• timestamps, distributed dependency checking and
• TO_DATE function
• trace files
  • described
  • log writer process and
• transaction control statements [2]
• transaction set consistency
• transaction set consistent
• transaction tables
  • reset at recovery
• TRANSACTIONS parameter
• TRANSACTIONS_PER_ROLLBACK_SEGMENT parameter
• transactions
  • assigning system change numbers
  • assigning to rollback segments
  • committing [2] [3] [4]
    • group commits
    • use of rollback segments
    • writing redo log buffers and
  • concurrency and
  • deadlocks and
  • described
  • discrete transactions
  • distributed
    • deadlocks and
    • resolving automatically
    • two-phase commit
    • two-phase commit and
  • distribution among rollback segments of
  • end of
  • in-doubt
    • resolving automatically [2]
    • resolving manually
    • rollback segments and
    • use partly available segments
  • manual locking of
  • overview of
  • read consistency of [2]
  • read-only [2]
    • not assigned to rollback segments
  • redo log files written before commit
  • rollback segments and
  • rolling back [2]
    • and offline tablespaces
    • partially
    • use of rollback segments
  • savepoints in [2]
  • serializable
  • space used in data blocks for
  • start of
  • statement level rollback and
  • system change numbers
  • terminating the application and
  • termination of
  • transaction control statements
  • triggers and
  • writing to rollback segments
• triggers
  • action
    • timing of
  • AFTER
  • as program units
  • auditing
  • BEFORE
  • can call procedures
  • cascading
  • constraints apply to
  • constraints contrasted with
  • correlation names use of
  • data access and
  • defined
  • dependency management of [2]
  • disabled
  • enabled
  • enforcing data integrity with
  • events
  • examples of [2]
  • firing (executing) [2]
    • privileges required
    • steps involved
    • timing of
  • INVALID status [2]
  • maintain data integrity
  • object dependencies of
  • overview of
  • parts of
  • privileges for executing
  • procedures contrasted with
  • prohibited in views
  • restrictions
  • row
  • sequence for firing multiple
  • shared SQL areas and
  • statement
  • storage of
  • types of
  • UNKNOWN does not fire
  • uses of
  • vs. Oracle Forms triggers
  • when to use instead of constraints
• Trusted Oracle
  • described
  • mandatory access control
  • MLS_LABEL datatype
  • mounting multiple databases in
• two-phase commit, described [2]
  • manual override of
• two-task mode
  • described
  • listener process and
  • network communication and
  • program interface in

  U

• undo
• unique indexes
• UNIQUE key constraints [2]
  • composite keys and nulls
  • indexes used to enforce
  • maximum number of columns in
  • NOT NULL constraints and
  • nulls and
  • size limit of
• unique keys [2]
• updatable join views
• UPDATE command
  • foreign key references and
  • freeing space in data blocks
• update intensive environments
• update restrict
• updates, location transparency and
• user processes
  • allocate PGA's
  • connections and
  • dedicated server processes and
  • sessions and
  • shared server processes and
• user program interface (UPI)
• USER pseudo-column
• USER_ views
• USER_TAB_COLUMNS view [2]
• USER_TABLES view
• USER_UPDATABLE_COLUMNS view
• users
  • access
    • rights
  • associated with schemas
  • auditing
  • authentication of
  • coordinating concurrent actions of
  • database links and
  • dedicated servers and
  • default tablespaces of
  • licensing by number of
  • licensing of
  • multi-user environments [2]
  • names of
  • password encryption
  • privileges of [2]
  • processes of [2]
  • profiles of [2]
  • PUBLIC user group
  • resource limits of [2]
  • restrictions on resource use of
  • roles and
    • for types of users
  • schemas of
  • security domains of [2] [3]
  • single-user Oracle
  • tablespace quotas of [2]
  • tablespaces of
  • temporary tablespaces of [2]
  • user names

  V

• V$LICENSE view
• V_$ and V$ objects
• VALID status [2]
• VARCHAR datatype
• VARCHAR2 datatype
  • non-padded comparison semantics
  • similarity to RAW datatype
  • when to use
• variables, in stored procedures
• viewed tables
• views
  • ALL_UPDATABLE_COLUMNS
  • altering base tables and
  • auditing [2]
  • constraints and triggers prohibited in
  • constraints indirectly affect
  • data dictionary use of
  • DBA_UPDATABLE_COLUMNS
  • definition expanded
  • dependency status of
  • histograms
  • how stored
  • indexes and
  • INVALID status
  • maximum number of columns in
  • NLS parameters in
  • object dependencies and
  • overview of [2]
  • partition views
  • prerequisites for compilation of
  • privileges for
  • security applications of
  • SQL functions in
  • USER_UPDATABLE_COLUMNS
  • uses of
  • VALID status
• virtual memory
• virtual tables

  W

• waits for blocking transaction
• writers block readers

  X

  Y

  Z