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* glossary
@ 2020-01-02 21:24 PG Doc comments form <[email protected]>
2020-01-07 10:29 ` Re: glossary Laurenz Albe <[email protected]>
0 siblings, 1 reply; 3+ messages in thread
From: PG Doc comments form @ 2020-01-02 21:24 UTC (permalink / raw)
To: [email protected]; +Cc: [email protected]
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/12/creating-cluster.html
Description:
It would be great to have a glossary as an appendix, to define concepts such
as cluster, schema, tablespace, database.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: glossary
2020-01-02 21:24 glossary PG Doc comments form <[email protected]>
@ 2020-01-07 10:29 ` Laurenz Albe <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Laurenz Albe @ 2020-01-07 10:29 UTC (permalink / raw)
To: [email protected]; [email protected]
On Thu, 2020-01-02 at 21:24 +0000, PG Doc comments form wrote:
> Page: https://www.postgresql.org/docs/12/creating-cluster.html
> Description:
>
> It would be great to have a glossary as an appendix, to define concepts such
> as cluster, schema, tablespace, database.
Does the index help?
https://www.postgresql.org/docs/current/bookindex.html
Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com
^ permalink raw reply [nested|flat] 3+ messages in thread
* [PATCH 1/2] glossary
@ 2020-03-19 21:29 Alvaro Herrera <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Alvaro Herrera @ 2020-03-19 21:29 UTC (permalink / raw)
---
doc/src/sgml/filelist.sgml | 1 +
doc/src/sgml/glossary.sgml | 1441 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/postgres.sgml | 1 +
3 files changed, 1443 insertions(+)
create mode 100644 doc/src/sgml/glossary.sgml
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
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--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
<!ENTITY limits SYSTEM "limits.sgml">
<!ENTITY acronyms SYSTEM "acronyms.sgml">
+<!ENTITY glossary SYSTEM "glossary.sgml">
<!ENTITY features-supported SYSTEM "features-supported.sgml">
<!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..cf20fb759c
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+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1441 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+ This is a list of terms and their meaning in the context of
+ <productname>PostgreSQL</productname> and relational database
+ systems in general.
+ </para>
+ <glosslist>
+ <glossentry id="glossary-aggregate">
+ <glossterm>Aggregate</glossterm>
+ <glossdef>
+ <para>
+ To combine a collection of data values into a single value, whose
+ value may not be of the same type as the original values.
+ <glossterm>Aggregate</glossterm> <glossterm>Functions</glossterm>
+ combine multiple <glossterm>Rows</glossterm> that share a common set
+ of values into one <glossterm>Row</glossterm>, which means that the
+ only data visible in the values in common, and the aggregates of the
+ non-common data.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="functions-aggregate">Aggregate Functions</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-analytic">
+ <glossterm>Analytic</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Function</glossterm> whose computed value can reference
+ values found in nearby <glossterm>Rows</glossterm> of the same
+ <glossterm>Result Set</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="tutorial-window">Window Functions</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-archiver">
+ <glossterm>Archiver</glossterm>
+ <glossdef>
+ <para>
+ A process that backs up <glossterm>WAL Files</glossterm> in order to
+ reclaim space on the file system.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="continuous-archiving">Backup and Restore: Continuous Archiving and Point-in-Time Recovery (PITR)</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-atomic">
+ <glossterm>Atomic</glossterm>
+ <glossdef>
+ <para>
+ In reference to the value of an <glossterm>Attribute</glossterm> or
+ <glossterm>Datum</glossterm>: cannot be broken down into smaller
+ components.
+ </para>
+ <para>
+ In reference to an operation: An event that cannot be completed in
+ part: it must either entirely succeed or entirely fail. A series of
+ <acronym>SQL</acronym> statements can be combined into a
+ <glossterm>Transaction</glossterm>, and that
+ <glossterm>transaction</glossterm> is said to be
+ <glossterm>Atomic</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-attribute">
+ <glossterm>Attribute</glossterm>
+ <glossdef>
+ <para>
+ An element with a certain name and data type found within a
+ <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-autovacuum">
+ <glossterm>Autovacuum</glossterm>
+ <glossdef>
+ <para>
+ Processes that remove outdated <acronym>MVCC</acronym>
+ <glossterm>Records</glossterm> of the <glossterm>Heap</glossterm> and
+ <glossterm>Index</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="routine-vacuuming">Routine Database Maintenance Tasks: Routine Vacuuming</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-backend-process">
+ <glossterm>Backend Process</glossterm>
+ <glossdef>
+ <para>
+ Processes of an <glossterm>Instance</glossterm> which act on behalf of
+ client <glossterm>Connections</glossterm> and handle their requests.
+ </para>
+ <para>
+ (Don't confuse this term with the similar terms <glossterm>Background
+ Worker</glossterm> or <glossterm>Background Writer</glossterm>).
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-backend-server">
+ <glossterm>Backend Server</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>Instance</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-background-worker">
+ <glossterm>Background Worker</glossterm>
+ <glossdef>
+ <para>
+ Individual processes within an <glossterm>Instance</glossterm>, which
+ run system- or user-supplied code. Typical use cases are processes
+ which handle parts of an <acronym>SQL</acronym> query to take
+ advantage of parallel execution on servers with multiple
+ <acronym>CPUs</acronym>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="bgworker">Background Worker Processes</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-background-writer">
+ <glossterm>Background Writer</glossterm>
+ <glossdef>
+ <para>
+ Writes continuously dirty pages from <glossterm>Shared
+ Memory</glossterm> to the file system. It starts periodically, but
+ works only for a short period in order to distribute expensive
+ <acronym>I/O</acronym> activity over time instead of generating fewer
+ large <acronym>I/O</acronym> peaks which could block other processes.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="runtime-config-resource">Server Configuration: Resource Consumption</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-cast">
+ <glossterm>Cast</glossterm>
+ <glossdef>
+ <para>
+ A conversion of a <glossterm>Datum</glossterm> from its current data
+ type to another data type.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-catalog">
+ <glossterm>Catalog</glossterm>
+ <glossdef>
+ <para>
+ The <acronym>SQL</acronym> standard uses this standalone term to
+ indicate what is called a <glossterm>Database</glossterm> in
+ <productname>PostgreSQL</productname>'s terminology.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-check-constraint">
+ <glossterm>Check Constraint</glossterm>
+ <glossdef>
+ <para>
+ A type of <glossterm>Constraint</glossterm> defined on a
+ <glossterm>Relation</glossterm> which restricts the values allowed in
+ one or more <glossterm>Attributes</glossterm>. The <glossterm>Check
+ Constraint</glossterm> can make reference to any
+ <glossterm>Attribute</glossterm> in the
+ <glossterm>Relation</glossterm>, but cannot reference other
+ <glossterm>Rows</glossterm> of the same
+ <glossterm>Relation</glossterm> or other
+ <glossterm>Relations</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="ddl-constraints">Constraints</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-checkpointer">
+ <glossterm>Checkpointer</glossterm>
+ <glossdef>
+ <para>
+ A process that writes dirty pages and <glossterm>WAL
+ Records</glossterm> to the file system and creates a special
+ checkpoint record. This process is initiated when predefined
+ conditions are met, such as a specified amount of time has passed, or
+ a certain volume of records have been collected.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-checkpoint">
+ <glossterm>Checkpoint</glossterm>
+ <glossdef>
+ <para>
+ A <link linkend="sql-checkpoint"> Checkpoint</link> is a point in time
+ when all older dirty pages of the <glossterm>Shared
+ Memory</glossterm>, all older <glossterm>WAL records</glossterm>, and
+ a special <glossterm>Checkpoint record</glossterm> have been written
+ and flushed to disk.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-cluster">
+ <glossterm>Cluster</glossterm>
+ <glossdef>
+ <para>
+ A group of <glossterm>Database</glossterm>s plus their
+ <glossterm>Global SQL Objects</glossterm>. The
+ <glossterm>Cluster</glossterm> is managed by exactly one
+ <glossterm>Instance</glossterm>. A newly created
+ <glossterm>Cluster</glossterm> will have three
+ <glossterm>Databases</glossterm> created automatically. They are
+ <literal>template0</literal>, <literal>template1</literal>, and
+ <literal>postgres</literal>. It is expected that an application will
+ create one or more additional <glossterm>Databases</glossterm> aside
+ from these three.
+ </para>
+ <para>
+ Don't confuse the <productname>PostgreSQL</productname> specific term
+ <glossterm>Cluster</glossterm> with the SQL command
+ <literal>CLUSTER</literal>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-column">
+ <glossterm>Column</glossterm>
+ <glossdef>
+ <para>
+ An <glossterm>Attribute</glossterm> found in a
+ <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-commit">
+ <glossterm>Commit</glossterm>
+ <glossdef>
+ <para>
+ The act of finalizing a <glossterm>Transaction</glossterm> within the
+ <glossterm>Database</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-commit">SQL Commands: COMMIT</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-concurrency">
+ <glossterm>Concurrency</glossterm>
+ <glossdef>
+ <para>
+ The concept that multiple independent operations happen within the
+ <glossterm>Database</glossterm> at the same time.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-connection">
+ <glossterm>Connection</glossterm>
+ <glossdef>
+ <para>
+ A <acronym>TCP/IP</acronym> or socket line for inter-process
+ communication. If the two involved processes reside on different
+ servers, <acronym>TCP/IP</acronym> must be used. Otherwise both
+ techniques are possible.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-constraint">
+ <glossterm>Constraint</glossterm>
+ <glossdef>
+ <para>
+ A concept of restricting the values of data allowed within a
+ <glossterm>Table</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="ddl-constraints">Constraints</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-data-area">
+ <glossterm>Data Area</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>Data Directory</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-data-directory">
+ <glossterm>Data Directory</glossterm>
+ <glossdef>
+ <para>
+ The base directory on the filesystem of a
+ <glossterm>Server</glossterm> that contains all data files and
+ subdirectories associated with a <glossterm>Cluster</glossterm> with
+ the exception of tablespaces. The environment variable
+ <literal>PGDATA</literal> often — but not always — referes to the
+ <glossterm>Data Directory</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-database">
+ <glossterm>Database</glossterm>
+ <glossdef>
+ <para>
+ A named collection of <glossterm>SQL Objects</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-database-server">
+ <glossterm>Database Server</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>Instance</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-datum">
+ <glossterm>Datum</glossterm>
+ <glossdef>
+ <para>
+ The internal representation of a <acronym>SQL</acronym> data type.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-delete">
+ <glossterm>Delete</glossterm>
+ <glossdef>
+ <para>
+ A <acronym>SQL</acronym> command whose purpose is to remove
+ <glossterm>Rows</glossterm> from a given <glossterm>Table</glossterm>
+ or <glossterm>Relation</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-delete">SQL Commands: DELETE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-file-segment">
+ <glossterm>File Segment</glossterm>
+ <glossdef>
+ <para>
+ If a heap or index file grows in size over 1 GB, it will be split
+ into multiple physical files. These files are called <glossterm>File
+ Segments</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+ </para>
+ <para>
+ (Don't confuse this term with the similar term
+ <glossterm>WAL Segment</glossterm>).
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-foreign-data-wrapper">
+ <glossterm>Foreign Data Wrapper</glossterm>
+ <glossdef>
+ <para>
+ A means of representing data that is not contained in the local
+ <glossterm>Database</glossterm> as if were in local
+ <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is
+ possible to define a <glossterm>Foreign Server</glossterm> and
+ <glossterm>Foreign Tables</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createforeigndatawrapper">SQL Commands: CREATE FOREIGN DATA WRAPPER</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-foreign-key">
+ <glossterm>Foreign Key</glossterm>
+ <glossdef>
+ <para>
+ A type of <glossterm>Constraint</glossterm> defined on one or more
+ <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
+ requires the value in those <glossterm>Column</glossterm>s to uniquely
+ identify a <glossterm>Row</glossterm> in the specified
+ <glossterm>Table</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-foreign-server">
+ <glossterm>Foreign Server</glossterm>
+ <glossdef>
+ <para>
+ A named collection of <glossterm>Foreign Tables</glossterm> which all
+ use the same <glossterm>Foreign Data Wrapper</glossterm> and have
+ other configuration values in common.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createserver">SQL Commands: CREATE SERVER</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-foreign-table">
+ <glossterm>Foreign Table</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Relation</glossterm> which appears to have
+ <glossterm>Rows</glossterm> and <glossterm>Columns</glossterm> similar
+ to a regular <glossterm>Table</glossterm>, but will forward requests
+ for data through its <glossterm>Foreign Data Wrapper</glossterm>,
+ which will return <glossterm>Result Sets</glossterm> structured
+ according to the definition of the <glossterm>Foreign Table</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createforeigntable">SQL Commands: CREATE FOREIGN TABLE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-function">
+ <glossterm>Function</glossterm>
+ <glossdef>
+ <para>
+ Any pre-defined transformation of data. Many
+ <glossterm>Functions</glossterm> are already defined within
+ <productname>PostgreSQL</productname> itself, but can also be
+ user-defined.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-global-sql-object">
+ <glossterm>Global SQL Object</glossterm>
+ <glossdef>
+ <para>
+ <!-- FIXME -->
+ Not all <glossterm>SQL Objects</glossterm> belong to a certain
+ <glossterm>Schema</glossterm>. Some belong to the complete
+ <glossterm>Database</glossterm>, or even to the complete
+ <glossterm>Cluster</glossterm>. These are referred to as
+ <glossterm>Global SQL Objects</glossterm>. Collations and Extensions
+ such as <glossterm>Foreign Data Wrappers</glossterm> reside at the
+ <glossterm>Database</glossterm> level; <glossterm>Database</glossterm>
+ names, <glossterm>Roles</glossterm>,
+ <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm>
+ origins, and subscriptions for logical
+ <glossterm>Replication</glossterm> at the
+ <glossterm>Cluster</glossterm> level.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-grant">
+ <glossterm>Grant</glossterm>
+ <glossdef>
+ <para>
+ A <acronym>SQL</acronym> command that is used to enable
+ <glossterm>Users</glossterm> or <glossterm>Roles</glossterm> to access
+ specific objects within the <glossterm>Database</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-grant">SQL Commands: GRANT</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-heap">
+ <glossterm>Heap</glossterm>
+ <glossdef>
+ <para>
+ Contains the original values of <glossterm>Row</glossterm> attributes
+ (i.e. the data). The <glossterm>Heap</glossterm> is realized within
+ <glossterm>Database</glossterm> files and mirrored in
+ <glossterm>Shared Memory</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-host">
+ <glossterm>Host</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>Server</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-index">
+ <glossterm>Index</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Relation</glossterm> that contains data derived from a
+ <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such
+ as a <glossterm>Materialized View</glossterm>). It's internal
+ structure supports very fast retrieval of and access to the original
+ data.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-insert">
+ <glossterm>Insert</glossterm>
+ <glossdef>
+ <para>
+ A <acronym>SQL</acronym> command used to add new data into a
+ <glossterm>Table</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-insert">SQL Commands: INSERT</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-instance">
+ <glossterm>Instance</glossterm>
+ <glossdef>
+ <para>
+ An <glossterm>Instance</glossterm> is a group of processes plus their
+ common <glossterm>Shared Memory</glossterm> running on a single
+ <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm>
+ handles all key features of a <acronym>DBMS</acronym>: read and write
+ access to files and <glossterm>Shared Memory</glossterm>, assurance of
+ the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+ <glossterm>Connections</glossterm> to client programms, backup,
+ recovery, replication, privileges, etc.
+ </para>
+ <para>
+ An <glossterm>Instance</glossterm> manages exactly one
+ <glossterm>Cluster</glossterm>.
+ </para>
+ <para>
+ Many <glossterm>Instances</glossterm> can run on the same server as
+ long as they use different <acronym>IP</acronym> ports and manage
+ different <glossterm>Cluster</glossterm>s. Different
+ <glossterm>Instances</glossterm> on a server may use the same or
+ different versions of <productname>PostgreSQL</productname>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-join">
+ <glossterm>Join</glossterm>
+ <glossdef>
+ <para>
+ A technique used with <command>SELECT</command> statements for
+ correlating data in one or more <glossterm>Relations</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-key">
+ <glossterm>Key</glossterm>
+ <glossdef>
+ <para>
+ A means of identifying a <glossterm>Row</glossterm> within a
+ <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by
+ values contained within one or more <glossterm>Attributes</glossterm>
+ in that <glossterm>Table</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-lock">
+ <glossterm>Lock</glossterm>
+ <glossdef>
+ <para>
+ A mechanism for one process temporarily preventing data from being
+ manipulated by any other process.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-log-file">
+ <glossterm>Log File</glossterm>
+ <glossdef>
+ <para>
+ <link linkend="logfile-maintenance">LOG files</link> contain readable
+ text lines about serious and non-serious events, e.g.: use of wrong
+ password, long-running queries, ... .
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-log-writer">
+ <glossterm>Log Writer</glossterm>
+ <glossdef>
+ <para>
+ If activated and parameterized, the
+ <link linkend="runtime-config-logging">Log Writer</link> process
+ writes information about database events into the current
+ <glossterm>Log file</glossterm>. When reaching certain time- or
+ volume-dependent criterias, he <!-- FIXME "he"? --> creates a new
+ <glossterm>Log file</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-log-record">
+ <glossterm>Log Record</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>WAL Record</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-logged">
+ <glossterm>Logged</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Table</glossterm> is considered
+ <glossterm>Logged</glossterm> if changes to it are sent to the
+ <glossterm>WAL Log</glossterm>. By default, all regular
+ <glossterm>Tables</glossterm> are <glossterm>Logged</glossterm>. A
+ <glossterm>Table</glossterm> can be speficied as unlogged either at
+ creation time or via the <command>ALTER TABLE</command> command. The
+ primary use of unlogged <glossterm>Tables</glossterm> is for storing
+ transient work data that must be shared across processes, but with a
+ final result stored in logged <glossterm>Tables</glossterm>.
+ <glossterm>Temporary Tables</glossterm> are always unlogged.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-master">
+ <glossterm>Master</glossterm>
+ <glossdef>
+ <para>
+ When two or more <glossterm>Databases</glossterm> are linked via
+ <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm>
+ that is considered the authoritative source of information is called
+ the <glossterm>Master</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-materialized">
+ <glossterm>Materialized</glossterm>
+ <glossdef>
+ <para>
+ The act of storing information rather than just the means of accessing
+ the information. This term is used in <glossterm>Materialized
+ Views</glossterm> meaning that the data derived from the
+ <glossterm>View</glossterm> is actually stored on disk separate from
+ the sources of that data. When the term
+ <glossterm>Materialized</glossterm> is used in speaking about
+ mulit-step queries, it means that the data of a given step is stored
+ (in memory, but that storage may spill over onto disk).
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-materialized-view">
+ <glossterm>Materialized View</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Relation</glossterm> that is defined in the same way that
+ a <glossterm>View</glossterm> is, but it stores data in the same way
+ that a <glossterm>Table</glossterm> does. it cannot be modified via
+ <command>INSERT</command>, <command>UPDATE</command>, or
+ <command>DELETE</command> operations.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-creatematerializedview">SQL Commands: CREATE MATERIALIZED VIEW</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-null">
+ <glossterm>Null</glossterm>
+ <glossdef>
+ <para>
+ A concept of non-existence that is a central tenet of Relational
+ Database Theory. It represents the absence of value.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-partition">
+ <glossterm>Partition</glossterm>
+ <glossdef>
+ <para>
+ <!-- FIXME should this use the style used in "atomic"? -->
+ a) A <glossterm>Table</glossterm> that can be queried independently by
+ its own name, but can also be queried via another
+ <glossterm>Table</glossterm>, a partitionend
+ <glossterm>Table</glossterm>, which is a collection of
+ sub-<glossterm>Table</glossterm>s, each capable of holding one defined
+ subset of information that does not overlap with any other
+ <glossterm>Table</glossterm> in the set of
+ <glossterm>Table</glossterm>s.
+ </para>
+ <para>
+ b) A defined boundary used in an <glossterm>Analytic</glossterm>
+ <glossterm>Function</glossterm> to identify which neighboring
+ <glossterm>Rows</glossterm> can be considered by the
+ <glossterm>Function</glossterm> for this particular
+ <glossterm>Row</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-postmaster">
+ <glossterm>Postmaster</glossterm>
+ <glossdef>
+ <para>
+ The very first process of an <glossterm>Instance</glossterm>. It
+ starts the other processes and creates <glossterm>Backend
+ Processes</glossterm> on demand.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="server-start">Server Setup and Operation: Starting the Database Server</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-primary-key">
+ <glossterm>Primary Key</glossterm>
+ <glossdef>
+ <para>
+ A special case of <glossterm>Unique Index</glossterm> defined on a
+ <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm>
+ that also guarantees that all of the <glossterm>Attributes</glossterm>
+ within the <glossterm>Primary Key</glossterm> do not have
+ <glossterm>Null</glossterm> values. As the name implies, there can be
+ only one <glossterm>Primary Key</glossterm> per
+ <glossterm>Table</glossterm>, though it is possible to have multiple
+ <glossterm>Unique Indexes</glossterm> that also have no
+ <glossterm>Null</glossterm>-capable <glossterm>Attributes</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-procedure">
+ <glossterm>Procedure</glossterm>
+ <glossdef>
+ <para>
+ A defined set of instructions for manipulating data within a
+ <glossterm>Database</glossterm>. <glossterm>Procedure</glossterm> can
+ be written in a variety of programming languages. They may seem
+ similar to <glossterm>Functions</glossterm> but are different in that
+ they must be invoked via the <command>CALL</command> command rather
+ than the <command>SELECT</command> or <command>PERFORM</command>
+ commands, and they are allowed to make transactional statements such
+ as <command>COMMIT</command> and <command>ROLLBACK</command>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createprocedure">SQL Commands: CREATE PROCEDURE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-record">
+ <glossterm>Record</glossterm>
+ <glossdef>
+ <para>
+ See <link linkend="sql-revoke">Tupple</link>.
+ </para>
+ <para>
+ A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm>
+ or other Relation.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-referential-integrity">
+ <glossterm>Referential Integrity</glossterm>
+ <glossdef>
+ <para>
+ The means of restricting data in one <glossterm>Relation</glossterm>
+ such that it must have matching data in another
+ <glossterm>Relation</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-relation">
+ <glossterm>Relation</glossterm>
+ <glossdef>
+ <para>
+ The generic term for all objects in a <glossterm>Database</glossterm>
+ that have a name and a list of <glossterm>Attributes</glossterm>
+ defined in a specific order. <glossterm>Tables</glossterm>,
+ <glossterm>Views</glossterm>, <glossterm>Foreign Tables</glossterm>,
+ <glossterm>Materialized Views</glossterm>, and
+ <glossterm>Indexes</glossterm> are all
+ <glossterm>Relations</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-replica">
+ <glossterm>Replica</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Database</glossterm> that is paired with a Master
+ <glossterm>Database</glossterm> and is maintaining a copy of some or
+ all of the Master <glossterm>Database</glossterm>'s data. The primary
+ reasons for doing this are to allow for greater access to that data,
+ and to maintain availability of the data in the event that the
+ <glossterm>Master</glossterm> becomes unavailable.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-replication">
+ <glossterm>Replication</glossterm>
+ <glossdef>
+ <para>
+ The act of reproducing data on one <glossterm>Server</glossterm> into
+ another called a <glossterm>Replica</glossterm>. This can take the
+ form of Physical <glossterm>Replication</glossterm>, where all file
+ changes from one <glossterm>Server</glossterm> are copied verbatim,
+ or Logical <glossterm>Replication</glossterm> where a defined subset
+ of data changes are conveyed.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-result-set">
+ <glossterm>Result Set</glossterm>
+ <glossdef>
+ <para>
+ A data structure transmitted from a <glossterm>Server</glossterm> to
+ client program upon the completion of a <acronym>SQL</acronym>
+ command, usually a <command>SELECT</command> but it can be an
+ <command>INSERT</command>, <command>UPDATE</command>, or
+ <command>DELETE</command> command if the <literal>RETURNING</literal>
+ clause is specified. The data structure consists of zero or more
+ <glossterm>Rows</glossterm> with the same ordered set of
+ <glossterm>Attributes</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-revoke">
+ <glossterm>Revoke</glossterm>
+ <glossdef>
+ <para>
+ A command to reduce access to a named set of
+ <glossterm>Database</glossterm> objects for a named list of
+ <glossterm>Users</glossterm> and <glossterm>Roles</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-revoke">SQL Commands: REVOKE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-role">
+ <glossterm>Role</glossterm>
+ <glossdef>
+ <para>
+ A collection of access privileges to the
+ <glossterm>Database</glossterm>. <glossterm>Roles</glossterm> are
+ themselves a privilege that can be granted to other roles. This is
+ often done for convenience or to ensure completeness when multiple
+ Users need the same privileges.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createrole">SQL Commands: CREATE ROLE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-rollback">
+ <glossterm>Rollback</glossterm>
+ <glossdef>
+ <para>
+ A command to undo all of the operations performed since the beginning
+ of a <glossterm>Transaction</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-rollback">SQL Commands: ROLLBACK</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-row">
+ <glossterm>Row</glossterm>
+ <glossdef>
+ <para>
+ See <link linkend="sql-revoke">Tupple</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-savepoint">
+ <glossterm>Savepoint</glossterm>
+ <glossdef>
+ <para>
+ A special mark (such as a timestamp) inside a
+ <glossterm>Transaction</glossterm>. Data modifications after this
+ point in time may be rolled back to the time of the savepoint.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-savepoint">SQL Commands: SAVEPOINT</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-schema">
+ <glossterm>Schema</glossterm>
+ <glossdef>
+ <para>
+ A <link linkend="ddl-schemas">schema</link> is a namespace for
+ <glossterm>SQL objects</glossterm>, which all reside in the same
+ <glossterm>database</glossterm>. Each <glossterm>SQL
+ object</glossterm> must reside in exactly one
+ <glossterm>Schema</glossterm>.
+ </para>
+ <para>
+ In general, the names of <glossterm>SQL objects</glossterm> in the
+ schema are unique - even across different types of objects. The lone
+ exception is the case of <glossterm>Unique</glossterm>
+ <glossterm>Constraint</glossterm>s, in which case there
+ <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm>
+ with the same name and <glossterm>Schema</glossterm> as the
+ <glossterm>Constraint</glossterm>. There is no restriction on having
+ a name used in multiple <glossterm>Schema</glossterm>s.
+ </para>
+ <para>
+ Many <glossterm>SQL objects</glossterm> reside in the default
+ <glossterm>Schema</glossterm> <literal>public</literal>, but it is
+ expected that more schemas are created to hold application specific
+ <glossterm>SQL objects</glossterm>.
+ </para>
+ <para>
+ More generically, the term <glossterm>Schema</glossterm> is used to
+ mean all data descriptions (<glossterm>Table</glossterm> definitions,
+ <glossterm>Constraint</glossterm>s, comments) for a given
+ <glossterm>Database</glossterm>. </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-segment">
+ <glossterm>Segment</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>File Segment</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-select">
+ <glossterm>Select</glossterm>
+ <glossdef>
+ <para>
+ The command used to query a <glossterm>Database</glossterm>. Normally,
+ <command>SELECT</command>s are not expected to modify the
+ <glossterm>Database</glossterm> in any way, but it is possible that
+ <glossterm>Functions</glossterm> invoked within the query could have
+ side-effects that do modify data. </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-serializable">
+ <glossterm>Serializable</glossterm>
+ <glossdef>
+ <para>
+ Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+ see changes made within other transactions. In effect, for the
+ initializing session the entire <glossterm>Database</glossterm>
+ appears to be frozen duration such a
+ <glossterm>Transaction</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-server">
+ <glossterm>Server</glossterm>
+ <glossdef>
+ <para>
+ The term <glossterm>Server</glossterm> denotes real hardware, a
+ container, or a Virtual Machine.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-session">
+ <glossterm>Session</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+ </para>
+ <para>
+ A description of the commands that were issued in the life cycle of a
+ particular <glossterm>Connection</glossterm> to the
+ <glossterm>Database</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-sequence">
+ <glossterm>Sequence</glossterm>
+ <glossdef>
+ <para>
+ <!-- sounds excessively complicated a definition -->
+ An <glossterm>Database</glossterm> object which represents the
+ mathematical concept of a numerical integral sequence. It can be
+ thought of as a <glossterm>Table</glossterm> with exactly one
+ <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The
+ value stored is known as the current value. A
+ <glossterm>Sequence</glossterm> has a defined direction (almost always
+ increasing) and an interval step (usually 1). Whenever the
+ <literal>NEXTVAL</literal> pseudo-column of a
+ <glossterm>Sequence</glossterm> is accessed, the current value is moved
+ in the defined direction by the defined interval step, and that value
+ is returned to the invoking query, and the current value of the
+ sequence is updated to reflect the new value. The value can be updated
+ multiple times in a single query, the net effect being that each row
+ selected will have a different value. Values taken from a
+ <glossterm>Sequence</glossterm> are never reverted even in the case of
+ a <glossterm>Rollback</glossterm>, which means that the
+ <glossterm>Sequence</glossterm> will never emit the same number twice,
+ and thus is the normal way of generating values to be put in a
+ <glossterm>Primary Key</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-shared-memory">
+ <glossterm>Shared Memory</glossterm>
+ <glossdef>
+ <para>
+ <acronym>RAM</acronym> which is used by the processes common to an
+ <glossterm>Instance</glossterm>. It mirrors parts of
+ <glossterm>Database</glossterm> files, provides an area for
+ <glossterm>WAL Records</glossterm>, and stores additional common
+ information. Note that <glossterm>Shared Memory</glossterm> belongs to
+ the complete <glossterm>Instance</glossterm>, not to a single
+ <glossterm>Database</glossterm>.
+ </para>
+ <para>
+ <glossterm>Shared Memory</glossterm> is organized into pages. If a
+ page is modified, it is called a dirty page until it is written back
+ to the file system.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="runtime-config-resource-memory">Server Configuration: Resource Consumption</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-sql-object">
+ <glossterm>SQL Object</glossterm>
+ <glossdef>
+ <para>
+ <!-- FIXME why enumerate each type? -->
+ A <glossterm>Table</glossterm>, <glossterm>View</glossterm>,
+ <glossterm>Materialized View</glossterm>,
+ <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>,
+ <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>,
+ <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>,
+ data type, or operator. Every <glossterm>SQL Object</glossterm>
+ belongs to exactly one <glossterm>Schema</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-stats-collector">
+ <glossterm>Stats Collector</glossterm>
+ <glossdef>
+ <para>
+ This process collects statistical information about the
+ <glossterm>Cluster</glossterm>'s activities.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="monitoring-stats">Monitoring Database Activity: The Statistics Collector</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-system-catalog">
+ <glossterm>System Catalog</glossterm>
+ <glossdef>
+ <para>
+ A collection of <glossterm>Table</glossterm>s and
+ <glossterm>View</glossterm>s which describe the structure of all
+ <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm>
+ and the <glossterm>Global SQL Objects</glossterm> of the
+ <glossterm>Cluster</glossterm>. The <glossterm>System
+ Catalog</glossterm> resides in the schema
+ <literal>pg_catalog</literal>. Main parts are mirrored as
+ <glossterm>Views</glossterm> in the <glossterm>Schema</glossterm>
+ <literal>information_schema</literal>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="ddl-schemas">Data Definition: Schemas</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-table">
+ <glossterm>Table</glossterm>
+ <glossdef>
+ <para>
+ A collection of <glossterm>Tuples</glossterm> (also known as
+ <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having
+ a common data structure (the same number of
+ <glossterm>Attributes</glossterm>s, in the same order, having the same
+ name and type per position). A <glossterm>Table</glossterm> is the
+ most common form of <glossterm>Relation</glossterm> in
+ <productname>PostgreSQL</productname>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-temporary-tables">
+ <glossterm>Temporary Tables</glossterm>
+ <glossdef>
+ <para>
+ <glossterm>Table</glossterm>s that exist either for the lifetime of a
+ <glossterm>Session</glossterm> or a
+ <glossterm>Transaction</glossterm>, as defined at creation time. The
+ data in them is not visible to other <glossterm>Sessions</glossterm>,
+ and is not <glossterm>Logged</glossterm>. <glossterm>Temporary
+ Tables</glossterm> are most often used to store intermediate data for
+ a multi-step data transformation.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-transaction">
+ <glossterm>Transaction</glossterm>
+ <glossdef>
+ <para>
+ A combination of one or more commands that must act as a single
+ <glossterm>Atomic</glossterm> command: they all succeed or fail
+ together, and their effects are not visible to other sessions until
+ the <glossterm>Transaction</glossterm> is complete.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="transaction-iso">Transaction Isolation</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-trigger">
+ <glossterm>Trigger</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Function</glossterm> which can be defined to execute
+ whenever a certain operation (<command>INSERT</command>,
+ <command>UPDATE</command>, or <command>DELTE</command>) is applied to
+ that <glossterm>Relation</glossterm>. A <glossterm>Trigger</glossterm>
+ executes within the same <glossterm>Transaction</glossterm> as the
+ statement which invoked it, and if the <glossterm>Function</glossterm>
+ fails then the invoking statement also fails.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createtrigger">SQL Commands: CREATE TRIGGER</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-tuple">
+ <glossterm>Tuple</glossterm>
+ <glossdef>
+ <para>
+ A collection of <glossterm>Attributes</glossterm> in a fixed order.
+ That order may be defined by the <glossterm>Table</glossterm> where
+ the <glossterm>Tuple</glossterm> is found, in which case the
+ <glossterm>Tuple</glossterm> is often called a
+ <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
+ also be defined by the structure of a <glossterm>Result
+ Set</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-unique">
+ <glossterm>Unique</glossterm>
+ <glossdef>
+ <para>
+ The condition of having no matching values in the same
+ <glossterm>Relation</glossterm>. Most often used in the concept of
+ <glossterm>Unique Indexes</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-unlogged">
+ <glossterm>Unlogged</glossterm>
+ <glossdef>
+ <para>
+ Changes to an unlogged <glossterm>Relation</glossterm> are not
+ reflected in the <glossterm>WAL Log</glossterm>. This disables
+ replication and crash recovery for such <glossterm>Relations</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-update">
+ <glossterm>Update</glossterm>
+ <glossdef>
+ <para>
+ A command used to modify <glossterm>Rows</glossterm> that already
+ exist in a specified <glossterm>Table</glossterm>. It cannot create
+ <glossterm>Rows</glossterm> nor can it remove
+ <glossterm>Rows</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-update">SQL Commands: UPDATE</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-user">
+ <glossterm>User</glossterm>
+ <glossdef>
+ <para>
+ A specific case of a <glossterm>Role</glossterm> that is entitled to
+ access (log into) the <glossterm>Database</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-user-mapping">
+ <glossterm>User Mapping</glossterm>
+ <glossdef>
+ <para>
+ The translation of user credentials in the local
+ <glossterm>Database</glossterm> to credentials in a remote data system
+ defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createusermapping">SQL Commands: CREATE USER MAPPING</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-view">
+ <glossterm>View</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>Relation</glossterm> that is defined by a
+ <command>SELECT</command> statement, but has no storage of its own.
+ Any time a query references a <glossterm>View</glossterm>, the
+ definition of the <glossterm>View</glossterm> is substituted into the
+ query as if the user had typed that subquery instead of the name of
+ the <glossterm>View</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="sql-createview">SQL Commands: CREATE VIEW</link>
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-file">
+ <glossterm>WAL File</glossterm>
+ <glossdef>
+ <para>
+ <glossterm>WAL Records</glossterm> are continously written to the end
+ of the current <glossterm>WAL File</glossterm>. <glossterm>WAL
+ Files</glossterm> as well as <glossterm>WAL Records</glossterm> belong
+ to the complete <glossterm>Cluster</glossterm>, not to a single
+ <glossterm>Database</glossterm>. After a <glossterm>WAL
+ File</glossterm> is full, a new <glossterm>WAL File</glossterm> is
+ created or, under certain conditions, one of the previous
+ <glossterm>WAL Files</glossterm> is renamed and reused.
+ </para>
+ <para>
+ The sequence of <glossterm>WAL Records</glossterm> in combination with
+ the sequence of <glossterm>WAL Files</glossterm> represents the
+ sequence of changes that have taken place in the
+ <glossterm>Cluster</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-log">
+ <glossterm>WAL Log</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>WAL File</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-record">
+ <glossterm>WAL Record</glossterm>
+ <glossdef>
+ <para>
+ A <glossterm>WAL Record</glossterm> contains either new or changed
+ <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or
+ information about a <command>COMMIT</command>,
+ <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or
+ <glossterm>Checkpointer</glossterm> operation. WAL records use a
+ non-printabe binary format.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-segment">
+ <glossterm>WAL Segment</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>WAL File</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-segment-file">
+ <glossterm>WAL Segment File</glossterm>
+ <glossdef>
+ <para>
+ See <glossterm>WAL File</glossterm>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-wal-writer">
+ <glossterm>WAL Writer</glossterm>
+ <glossdef>
+ <para>
+ This process writes <glossterm>WAL Records</glossterm> from
+ <glossterm>Shared Memory</glossterm> to <glossterm>WAL
+ Files</glossterm>.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="runtime-config-wal">Server Configuration: Write Ahead Log</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry id="glossary-window-function">
+ <glossterm>Window Function</glossterm>
+ <glossdef>
+ <para>
+ A type of <glossterm>Function</glossterm> similar to an
+ <glossterm>Aggregate</glossterm> in that can derive its value from a
+ set of <glossterm>Rows</glossterm> in a <glossterm>Result
+ Set</glossterm>, but still retaining the original source data.
+ </para>
+ <para>
+ For more information, see
+ <link linkend="tutorial-window">Window Functions</link>.
+ </para>
+ </glossdef>
+ </glossentry>
+ </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..2183e33bea 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
&docguide;
&limits;
&acronyms;
+ &glossary;
</part>
--
2.20.1
--mYCpIKhGyMATD0i+
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="0002-Change-all-For-more-info-see-X-links-to-xref-style.patch"
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