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Migration to Version 18.1Manual ChaptersPG18E.5.1. Migration to Version 18.1 A dump/restore is not required for those running 18.X.Migration to Version 18.1 Migration to Version 18.2Manual ChaptersPG18E.4.1. Migration to Version 18.2 A dump/restore is not required for those running 18.X. However, if you have any indexes on ltree columns, it may be necessary to reindex them after updating.…Migration to Version 18.2 Migration to Version 18.3Manual ChaptersPG18E.3.1. Migration to Version 18.3 A dump/restore is not required for those running 18.X. However, if you are upgrading from a version earlier than 18.2, see Section E.4.Migration to Version 18.3 Migration to Version 18.4Manual ChaptersPG18E.2.1. Migration to Version 18.4 A dump/restore is not required for those running 18.X. However, if you are upgrading from a version earlier than 18.2, see Section E.4.Migration to Version 18.4 Migration to Version 18.6Manual ChaptersPG18E.1.1. Migration to Version 18.6 A dump/restore is not required for those running 18.X. However, the first three security entries below describe configuration adjustments and data cleanups t…Migration to Version 18.6 mimeoExtensionsExtensionsExtension for specialized, per-table replication between PostgreSQL instances mimeo Replication and streamsReplication and streams · Extensions minFunctionsReferencemin Aggregate Functions 10 minimum value of expression across all non-null input values min ( expression ) → same as argument type minimum value of expression across all non-null input value…Functions · Aggregate Functions min_dynamic_shared_memoryConfigurationReferencemin_dynamic_shared_memory Resource Usage 14 Specifies the amount of memory that should be allocated at server startup for use by parallel queries. When this memory region is insufficient or …Configuration · Resource Usage min_eager_agg_group_sizeConfigurationReferencemin_eager_agg_group_size Query Tuning 19 Sets the minimum average group size required to consider applying eager aggregation. This helps avoid the overhead of eager aggregation when it does …Configuration · Query Tuning min_parallel_index_scan_sizeConfigurationReferencemin_parallel_index_scan_size Query Tuning 10 Sets the minimum amount of index data that must be scanned in order for a parallel scan to be considered. Note that a parallel index scan typical…Configuration · Query Tuning min_parallel_relation_sizeConfigurationReferencemin_parallel_relation_size Query Tuning 9.6 Sets the minimum size of relations to be considered for parallel scan. The default is 8 megabytes (8MB). PostgreSQL describes min_parallel_relatio…Configuration · Query Tuning min_parallel_table_scan_sizeConfigurationReferencemin_parallel_table_scan_size Query Tuning 10 Sets the minimum amount of table data that must be scanned in order for a parallel scan to be considered. For a parallel sequential scan, the amo…Configuration · Query Tuning min_protocol_versionCommand-line ToolsPG18min_protocol_version Specifies the minimum protocol version to allow for the connection. The default is to allow any version of the PostgreSQL protocol supported by libpq, which currently me…Database Connection Control Functions › Parameter Key Words min_scaleFunctionsReferencemin_scale Mathematical Functions And Operators 13 Minimum scale (number of fractional decimal digits) needed to represent the supplied value precisely min_scale ( numeric ) → integer Minimum…Functions · Mathematical Functions And Operators min_to_maxExtensionsExtensionsaggregates and functions for PostgreSQL Server aggregates c custom-aggregates extension functions postgresql postgresql-extension min_to_max Functions and aggregatesFunctions and aggregates · Extensions min_wal_sizeConfigurationReferencemin_wal_size Write-Ahead Log 10 As long as WAL disk usage stays below this setting, old WAL files are always recycled for future use at a checkpoint, rather than removed. This can be used to…Configuration · Write-Ahead Log MinGWManual ChaptersPG1817.7.3. MinGW PostgreSQL for Windows can be built using MinGW, a Unix-like build environment for Windows. It is recommended to use the MSYS2 environment for this and also to install any prer…MinGW Minor VersionsManual ChaptersPG1836.10.6.2.2. Minor Versions PostgreSQL makes an effort to avoid server API breaks in minor releases. In general, extension code that compiles and works with a minor release should also compi…Minor Versions Minor VersionsManual ChaptersPG1836.10.6.3.2. Minor Versions PostgreSQL makes an effort to avoid server ABI breaks in minor releases. In general, an extension compiled against any minor release should work with any other mi…Minor Versions mipt-asjExtensionsExtensionsAbbreviation-aware approximate string joins using the Tao-Deng-Stonebraker algorithm approximate-join similarity string mipt_asj Full-text searchFull-text search · Extensions MiscellaneousManual ChaptersPG1817.3.3.5. Miscellaneous It's fairly common, particularly for test builds, to adjust the default port number with --with-pgport. The other options in this section are recommended only for adv…Miscellaneous MiscellaneousManual ChaptersPG1817.4.3.6. Miscellaneous -Dpgport=NUMBER # Set NUMBER as the default port number for server and clients. The default is 5432. The port can always be changed later on, but if you specify it he…Miscellaneous MiscellaneousManual ChaptersPG18F.40.5.6. Miscellaneous We reject the LOAD command across the board, because any module loaded could easily circumvent security policy enforcement.Miscellaneous Miscellaneous Coding ConventionsManual ChaptersPG1855.4. Miscellaneous Coding Conventions C Standard # Code in PostgreSQL should only rely on language features available in the C99 standard. That means a conforming C99 compiler has to be abl…Miscellaneous Coding Conventions Miscellaneous FunctionsManual ChaptersPG1832.12. Miscellaneous Functions As always, there are some functions that just don't fit anywhere. PQfreemem Frees memory allocated by libpq. void PQfreemem(void *ptr); Frees memory allocated …Miscellaneous Functions mmddyyyyExtensionsExtensionsEducational date type with B-tree, wildcard patterns, and GiST nearest-neighbor search date gist education pg-mm-dd-yyyy Time seriesTime series · Extensions mobilitydbExtensionsExtensionsMobilityDB geospatial trajectory data management & analysis platform mobilitydb GeospatialGeospatial · Extensions mobilitydb_datagenExtensionsExtensionsMobilityDB random data generator functions mobilitydb GeospatialGeospatial · Extensions modFunctionsReferencemod Mathematical Functions And Operators 10 remainder of y/x mod ( y, x ) → (same as argument types) remainder of y/x 11 12 13 Remainder of y/x; available for smallint, integer, bigint, and …Functions · Mathematical Functions And Operators moddatetimeExtensionsExtensionsfunctions for tracking last modification time moddatetime Functions and aggregatesFunctions and aggregates · Extensions moddatetime — Functions for Tracking Last Modification TimeManual ChaptersPG18F.41.4. moddatetime — Functions for Tracking Last Modification Time moddatetime() is a trigger that stores the current time into a timestamp field. This can be useful for tracking the last m…moddatetime — Functions for Tracking Last Modification Time modeFunctionsReferencemode Aggregate Functions 10 returns the most frequent input value (arbitrarily choosing the first one if there are multiple equally-frequent results) mode ( ) WITHIN GROUP (ORDER BY sort_exp…Functions · Aggregate Functions modeshape_bsonExtensionsExtensionsPostgreSQL extension to convert ModeShape BSON to and from JSON bson json modeshape modeshape_bson UtilitiesUtilities · Extensions Modifying ArraysManual ChaptersPG188.15.4. Modifying Arrays An array value can be replaced completely: UPDATE sal_emp SET pay_by_quarter = '{25000,25000,27000,27000}' WHERE name = 'Carol'; or using the ARRAY expression syntax…Modifying Arrays Modifying Composite TypesManual ChaptersPG188.16.4. Modifying Composite Types Here are some examples of the proper syntax for inserting and updating composite columns. First, inserting or updating a whole column: INSERT INTO mytab (co…Modifying Composite Types Modifying TablesManual ChaptersPG185.7. Modifying Tables When you create a table and you realize that you made a mistake, or the requirements of the application change, you can drop the table and create it again. But this is …Modifying Tables mods_since_analyzeExtensionsExtensionsEstimation of number of changed tuples analyze changed tuples estimation mods_since_analyze MonitoringMonitoring · Extensions mogipixExtensionsExtensionsPostgreSQL extension exposing HEALPix and MOC Rust functions to SQL. astronomy astrophysics healpix moc pgrx mogipix GeospatialGeospatial · Extensions molecular_formulasExtensionsExtensionsMolecular-formula parser and strongly typed PostgreSQL data type chemistry molecular-formula pgrx emi_monorepo Data typesData types · Extensions Monetary TypesManual ChaptersPG188.2. Monetary Types The money type stores a currency amount with a fixed fractional precision; see Table 8.3. The fractional precision is determined by the database's lc_monetary setting. Th…Monetary Types