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Monitoring Disk UsageManual ChaptersPG18This section discusses how to monitor the disk usage of a PostgreSQL database system. monitoring_roleExtensionsExtensionsMonitoring · ExtensionsSecurity-definer monitoring wrappers for a non-privileged role monitoring role security-definer monitoring_role Monitoring monqExtensionsExtensionsCompatibility · ExtensionsMongoDB-like query support for jsonb data jsonb mongodb query monq Compatibility morpheme_funcsExtensionsExtensionsFull-text search · ExtensionsPostgreSQL extension built with pgrx; upstream metadata did not provide a specific description. japanese mecab morphology pgrx similarity morpheme_funcs Full-text search moss_uuidgenExtensionsExtensionsFunctions and aggregates · ExtensionsGenerates UUIDs for moss. We use this because there was no UUID type when moss was written, and I do not want to rewrite moss to use pgsql's uuid type moss_uuidgen Functions and aggregates mot_fdwExtensionsExtensionsForeign data wrappers · ExtensionsopenGauss memory-optimized table engine FDW adapter opengauss Foreign data wrappers MOVEManual ChaptersPG18Cursors[ direction { FROM | IN } ] cursor; MOVE repositions a cursor without retrieving any data. MOVE works like the FETCH command, except it only repositions the cursor and does not return the ro… MOVEManual ChaptersPG18position a cursor Synopsis MOVE [ direction ] [ FROM | IN ] cursor_name where direction can be one of: NEXT PRIOR FIRST LAST ABSOLUTE count RELATIVE count count ALL FORWARD FORWARD count FOR… Moving-Aggregate ModeManual ChaptersPG18User-Defined AggregatesAggregate functions can optionally support moving-aggregate mode, which allows substantially faster execution of aggregate functions within windows with moving frame starting points. (See Se… mpartmanExtensionsExtensionsAnalytics · ExtensionsModern partition manager for PostgreSQL mpartman Analytics mtmExtensionsExtensionsFunctions and aggregates · Extensionsaggregate to find min and max mtm Functions and aggregates mtreeExtensionsExtensionsAI and vectors · ExtensionsMetric-space index access method derived from PostgreSQL GiST gist index metric-space mtree AI and vectors mufdwExtensionsExtensionsForeign data wrappers · ExtensionsMinimal local-table foreign data wrapper for teaching mufdw Foreign data wrappers multicdr_fdwExtensionsExtensionsForeign data wrappers · ExtensionsForeign data wrapper for reading call-detail-record file streams as external SQL tables. cdr external-data fdw sql-med multicdr_fdw Foreign data wrappers Multicolumn IndexesManual ChaptersPG18An index can be defined on more than one column of a table. For example, if you have a table of this form: CREATE TABLE test2 ( major int, minor int, name varchar ); (say, you keep your /dev… multicornExtensionsExtensionsForeign data wrappers · ExtensionsFetch foreign data in Python in your PostgreSQL server. multicorn Foreign data wrappers Multiple Identity ColumnsManual ChaptersPG18CREATE TABLEPostgreSQL allows a table to have more than one identity column. The standard specifies that a table can have at most one identity column. This is relaxed mainly to give more flexibility for… Multiple Statements in a Simple QueryManual ChaptersPG18Message FlowWhen a simple Query message contains more than one SQL statement (separated by semicolons), those statements are executed as a single transaction, unless explicit transaction control command… Multiple Synchronous StandbysManual ChaptersPG18Log-Shipping Standby ServersSynchronous replication supports one or more synchronous standby servers; transactions will wait until all the standby servers which are considered as synchronous confirm receipt of their da… Multivalued ResultsManual ChaptersPG18xml2 — XPath querying and XSLT functionalityThe xpath_table function assumes that the results of each XPath query might be multivalued, so the number of rows returned by the function may not be the same as the number of input document… Multivariate MCV ListsManual ChaptersPG18Statistics Used by the PlannerAnother type of statistic stored for each column are most-common value lists. This allows very accurate estimates for individual columns, but may result in significant misestimates for queri… Multivariate N-Distinct CountsManual ChaptersPG18Multivariate Statistics ExamplesA similar problem occurs with estimation of the cardinality of sets of multiple columns, such as the number of groups that would be generated by a GROUP BY clause. When GROUP BY lists a sing… Multivariate N-Distinct CountsManual ChaptersPG18Statistics Used by the PlannerSingle-column statistics store the number of distinct values in each column. Estimates of the number of distinct values when combining more than one column (for example, for GROUP BY a, b) a… Multivariate Statistics ExamplesManual ChaptersPG18 Multixacts and WraparoundManual ChaptersPG18Routine VacuumingMultixact IDs are used to support row locking by multiple transactions. Since there is only limited space in a tuple header to store lock information, that information is encoded as a “multi… mumakExtensionsExtensionsUtilities · ExtensionsCardano CBOR parser blockchain cardano cbor pgrx mumak Utilities musicbrainz_collateExtensionsExtensionsUtilities · ExtensionsProvides Unicode Collation Algorithm support collation icu unicode postgresql_musicbrainz_collate Utilities musicbrainz_unaccentExtensionsExtensionsFull-text search · ExtensionsRemoves accents from Unicode data accents canonicalization fts musicbrainz unaccent unicode postgresql_musicbrainz_unaccent Full-text search mv_rewriteExtensionsExtensionsFeatures · ExtensionsQuery rewriting extension that transparently rewrites queries to use lower-cost materialized views. materialized-view planner query-rewrite pg_fdw_mv_rewrite Features mv_statsExtensionsExtensionsMonitoring · ExtensionsTracks creation, alteration, refresh, and reset statistics for materialized views. event-trigger materialized-view statistics mv_stats Monitoring mvtblExtensionsExtensionsAdministration · ExtensionsEasily move tables around tablespaces mvtbl Administration my_extensionExtensionsExtensionsFeatures · ExtensionsA Basic PostgreSQL Extension calculation data extension gsoc postgresql postgresql-extension tutorial utility my_extension Features myextExtensionsExtensionsAdministration · ExtensionsA useful and a flexible pattern for reloading postgres SQL extensions without losing data in extension-managed tables. pgsql postgres sql myext Administration myhelperExtensionsExtensionsUtilities · ExtensionsCollection of PostgreSQL helper functions admin array datetime diagnostics utility myhelper Utilities mypg_shardingExtensionsExtensionsAnalytics · Extensionsmypg sharding utilities for PostgreSQL distributed postgres-fdw sharding mypg_sharding Analytics mysql_fdwExtensionsExtensionsForeign data wrappers · ExtensionsForeign data wrapper for querying a MySQL server mysql_fdw Foreign data wrappers mysql_migratorExtensionsExtensionsReplication and streams · ExtensionsTools for MySQL to PostgreSQL migration mysql_migrator Replication and streams mysqlcompatExtensionsExtensionsCompatibility · ExtensionsMySQL compatibility functions, aggregates, operators, and casts for PostgreSQL porting. compatibility conversion function mysql porting mysqlcompat Compatibility nablaExtensionsExtensionsFeatures · ExtensionsAsynchronous incremental materialized views with delta subscriptions ivm logical-decoding subscriptions nabla Features Named SQL Descriptor AreasManual ChaptersPG18Using Descriptor AreasA named SQL descriptor area consists of a header, which contains information concerning the entire descriptor, and one or more item descriptor areas, which basically each describe one column…