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macaddr8Manual ChaptersPG188.9.5. macaddr8 The macaddr8 type stores MAC addresses in EUI-64 format, known for example from Ethernet card hardware addresses (although MAC addresses are used for other purposes as well).…macaddr8 macOSManual ChaptersPG18J.2.4. macOS If you use MacPorts, the following will get you set up: sudo port install docbook-xml docbook-xsl-nons libxslt fop If you use Homebrew, use this: brew install docbook docbook-xs…macOS macOSManual ChaptersPG1817.7.2. macOS To build PostgreSQL from source on macOS, you will need to install Apple's command line developer tools, which can be done by issuing xcode-select --install (note that this wil…macOS Main FunctionsManual ChaptersPG1832.3.1. Main Functions PQexec # Submits a command to the server and waits for the result. PGresult *PQexec(PGconn *conn, const char *command); Returns a PGresult pointer or possibly a null p…Main Functions Maintenance for Inheritance PartitioningManual ChaptersPG185.12.3.2. Maintenance for Inheritance Partitioning To remove old data quickly, simply drop the child table that is no longer necessary: DROP TABLE measurement_y2006m02; To remove the child t…Maintenance for Inheritance Partitioning Major VersionsManual ChaptersPG1836.10.6.2.1. Major Versions There is no promise of API compatibility between PostgreSQL major versions. Extension code therefore might require source code changes to work with multiple major…Major Versions Major VersionsManual ChaptersPG1836.10.6.3.1. Major Versions Servers of different major versions have intentionally incompatible ABIs. Extensions that use server APIs must therefore be re-compiled for each major release. Th…Major Versions Making a Base BackupManual ChaptersPG1825.3.2. Making a Base Backup The easiest way to perform a base backup is to use the pg_basebackup tool. It can create a base backup either as regular files or as a tar archive. If more flexi…Making a Base Backup Making a Base Backup Using the Low Level APIManual ChaptersPG1825.3.4. Making a Base Backup Using the Low Level API Instead of taking a full or incremental base backup using pg_basebackup, you can take a base backup using the low-level API. This procedu…Making a Base Backup Using the Low Level API Making an Incremental BackupManual ChaptersPG1825.3.3. Making an Incremental Backup You can use pg_basebackup to take an incremental backup by specifying the --incremental option. You must supply, as an argument to --incremental, the bac…Making an Incremental Backup Managing CollationsManual ChaptersPG1823.2.2. Managing Collations A collation is an SQL schema object that maps an SQL name to locales provided by libraries installed in the operating system. A collation definition has a provide…Managing Collations Managing Configuration File ContentsManual ChaptersPG1819.1.5. Managing Configuration File Contents PostgreSQL provides several features for breaking down complex postgresql.conf files into sub-files. These features are especially useful when ma…Managing Configuration File Contents Managing Database ConnectionsManual ChaptersPG1834.2. Managing Database Connections This section describes how to open, close, and switch database connections.Managing Database Connections Managing DatabasesManual ChaptersPG18Chapter 22. Managing Databases Every instance of a running PostgreSQL server manages one or more databases. Databases are therefore the topmost hierarchical level for organizing SQL objects …Managing Databases Managing Kernel ResourcesManual ChaptersPG1818.4. Managing Kernel Resources PostgreSQL can sometimes exhaust various operating system resource limits, especially when multiple copies of the server are running on the same system, or in…Managing Kernel Resources Managing TransactionsManual ChaptersPG1834.3.3. Managing Transactions In the default mode, statements are committed only when EXEC SQL COMMIT is issued. The embedded SQL interface also supports autocommit of transactions (similar …Managing Transactions Manipulating DocumentsManual ChaptersPG1812.4.1. Manipulating Documents Section 12.3.1 showed how raw textual documents can be converted into tsvector values. PostgreSQL also provides functions and operators that can be used to man…Manipulating Documents Manipulating QueriesManual ChaptersPG1812.4.2. Manipulating Queries Section 12.3.2 showed how raw textual queries can be converted into tsquery values. PostgreSQL also provides functions and operators that can be used to manipula…Manipulating Queries ManpagesManual ChaptersPG18J.3.2. Manpages We use the DocBook XSL stylesheets to convert DocBook refentry pages to *roff output suitable for man pages. To create the man pages, use the command: doc/src/sgml$ make manManpages Mapping Tables to XMLManual ChaptersPG189.15.4. Mapping Tables to XML The following functions map the contents of relational tables to XML values. They can be thought of as XML export functionality: table_to_xml ( table regclass, …Mapping Tables to XML Mappings between SQL and XML Data Types and ValuesManual ChaptersPG18D.3.1.3. Mappings between SQL and XML Data Types and Values In SQL:2006 and later, both directions of conversion between standard SQL data types and the XML Schema types are specified precis…Mappings between SQL and XML Data Types and Values Materialized ViewsManual ChaptersPG1839.3. Materialized Views Materialized views in PostgreSQL use the rule system like views do, but persist the results in a table-like form. The main differences between: CREATE MATERIALIZED V…Materialized Views Mathematical Functions and OperatorsManual ChaptersPG189.3. Mathematical Functions and Operators Mathematical operators are provided for many PostgreSQL types. For types without standard mathematical conventions (e.g., date/time types) we descri…Mathematical Functions and Operators MCV ListsManual ChaptersPG1869.2.3. MCV Lists As explained in Section 69.2.1, functional dependencies are very cheap and efficient type of statistics, but their main limitation is their global nature (only tracking dep…MCV Lists Measuring Executor Timing OverheadManual ChaptersPG18Measuring Executor Timing Overhead When the query executor is running a statement using EXPLAIN ANALYZE, individual operations are timed as well as showing a summary. The overhead of your sy…Measuring Executor Timing Overhead MechanicsManual ChaptersPG1856.2.1. Mechanics This section describes how to implement native language support in a program or library that is part of the PostgreSQL distribution. Currently, it only applies to C program…Mechanics MemoryManual ChaptersPG1819.4.1. Memory shared_buffers (integer) Sets the amount of memory the database server uses for shared memory buffers. The default is typically 128 megabytes (128MB), but might be less if you…Memory Memory ManagementManual ChaptersPG1845.3. Memory Management PostgreSQL allocates memory within memory contexts, which provide a convenient method of managing allocations made in many different places that need to live for diff…Memory Management MERGEManual ChaptersPG18MERGE MERGE — conditionally insert, update, or delete rows of a table Synopsis [ WITH with_query [, ...] ] MERGE INTO [ ONLY ] target_table_name [ * ] [ [ AS ] target_alias ] USING data_sour…MERGE Merge Support FunctionsManual ChaptersPG189.23. Merge Support Functions PostgreSQL includes one merge support function that may be used in the RETURNING list of a MERGE command to identify the action taken for each row; see Table 9.…Merge Support Functions MERGESManual ChaptersPG1836.15.6. MERGES The MERGES clause, if present, tells the system that it is permissible to use the merge-join method for a join based on this operator. MERGES only makes sense for a binary op…MERGES meson Build TargetsManual ChaptersPG1817.4.4. meson Build Targets Individual build targets can be built using ninja target. When no target is specified, everything except documentation is built. Individual build products can be …meson Build Targets meson setup OptionsManual ChaptersPG1817.4.3. meson setup Options meson setup's command-line options are explained below. This list is not exhaustive (use meson configure --help to get one that is). The options not covered here …meson setup Options Message Data TypesManual ChaptersPG1854.6. Message Data Types This section describes the base data types used in messages. Intn(i) An n-bit integer in network byte order (most significant byte first). If i is specified it is th…Message Data Types Message FlowManual ChaptersPG1854.2. Message Flow This section describes the message flow and the semantics of each message type. (Details of the exact representation of each message appear in Section 54.7.) There are sev…Message Flow Message FormatsManual ChaptersPG1854.7. Message Formats This section describes the detailed format of each message. Each is marked to indicate that it can be sent by a frontend (F), a backend (B), or both (F & B). Notice tha…Message Formats Message-Writing GuidelinesManual ChaptersPG1856.2.2. Message-Writing Guidelines Here are some guidelines for writing messages that are easily translatable. Do not construct sentences at run-time, like: printf("Files were %s.\n", flag ?…Message-Writing Guidelines Messaging OverviewManual ChaptersPG1854.1.1. Messaging Overview All communication is through a stream of messages. The first byte of a message identifies the message type, and the next four bytes specify the length of the rest …Messaging Overview Meta-CommandsManual ChaptersPG18Meta-Commands Anything you enter in psql that begins with an unquoted backslash is a psql meta-command that is processed by psql itself. These commands make psql more useful for administrati…Meta-Commands MetaphoneManual ChaptersPG18F.16.4. Metaphone Metaphone, like Soundex, is based on the idea of constructing a representative code for an input string. Two strings are then deemed similar if they have the same codes. Th…Metaphone