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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
| commit | 6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch) | |
| tree | 657d8194422a5daccecfd42d654b8a245ef7b4c8 /doc/src/sgml/html/bki.html | |
| parent | Initial commit. (diff) | |
| download | postgresql-13-upstream.tar.xz postgresql-13-upstream.zip | |
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/src/sgml/html/bki.html')
| -rw-r--r-- | doc/src/sgml/html/bki.html | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/doc/src/sgml/html/bki.html b/doc/src/sgml/html/bki.html new file mode 100644 index 0000000..d9e133c --- /dev/null +++ b/doc/src/sgml/html/bki.html @@ -0,0 +1,60 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 70. System Catalog Declarations and Initial Contents</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="storage-page-layout.html" title="69.6. Database Page Layout" /><link rel="next" href="system-catalog-declarations.html" title="70.1. System Catalog Declaration Rules" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">Chapter 70. System Catalog Declarations and Initial Contents</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="storage-page-layout.html" title="69.6. Database Page Layout">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="internals.html" title="Part VII. Internals">Up</a></td><th width="60%" align="center">Part VII. Internals</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="system-catalog-declarations.html" title="70.1. System Catalog Declaration Rules">Next</a></td></tr></table><hr></hr></div><div class="chapter" id="BKI"><div class="titlepage"><div><div><h2 class="title">Chapter 70. System Catalog Declarations and Initial Contents</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="sect1"><a href="system-catalog-declarations.html">70.1. System Catalog Declaration Rules</a></span></dt><dt><span class="sect1"><a href="system-catalog-initial-data.html">70.2. System Catalog Initial Data</a></span></dt><dd><dl><dt><span class="sect2"><a href="system-catalog-initial-data.html#SYSTEM-CATALOG-INITIAL-DATA-FORMAT">70.2.1. Data File Format</a></span></dt><dt><span class="sect2"><a href="system-catalog-initial-data.html#SYSTEM-CATALOG-OID-ASSIGNMENT">70.2.2. OID Assignment</a></span></dt><dt><span class="sect2"><a href="system-catalog-initial-data.html#SYSTEM-CATALOG-OID-REFERENCES">70.2.3. OID Reference Lookup</a></span></dt><dt><span class="sect2"><a href="system-catalog-initial-data.html#SYSTEM-CATALOG-AUTO-ARRAY-TYPES">70.2.4. Automatic Creation of Array Types</a></span></dt><dt><span class="sect2"><a href="system-catalog-initial-data.html#SYSTEM-CATALOG-RECIPES">70.2.5. Recipes for Editing Data Files</a></span></dt></dl></dd><dt><span class="sect1"><a href="bki-format.html">70.3. <acronym class="acronym">BKI</acronym> File Format</a></span></dt><dt><span class="sect1"><a href="bki-commands.html">70.4. <acronym class="acronym">BKI</acronym> Commands</a></span></dt><dt><span class="sect1"><a href="bki-structure.html">70.5. Structure of the Bootstrap <acronym class="acronym">BKI</acronym> File</a></span></dt><dt><span class="sect1"><a href="bki-example.html">70.6. BKI Example</a></span></dt></dl></div><p> + <span class="productname">PostgreSQL</span> uses many different system catalogs + to keep track of the existence and properties of database objects, such as + tables and functions. Physically there is no difference between a system + catalog and a plain user table, but the backend C code knows the structure + and properties of each catalog, and can manipulate it directly at a low + level. Thus, for example, it is inadvisable to attempt to alter the + structure of a catalog on-the-fly; that would break assumptions built into + the C code about how rows of the catalog are laid out. But the structure + of the catalogs can change between major versions. + </p><p> + The structures of the catalogs are declared in specially formatted C + header files in the <code class="filename">src/include/catalog/</code> directory of + the source tree. In particular, for each catalog there is a header file + named after the catalog (e.g., <code class="filename">pg_class.h</code> + for <code class="structname">pg_class</code>), which defines the set of columns + the catalog has, as well as some other basic properties such as its OID. + Other critical files defining the catalog structure + include <code class="filename">indexing.h</code>, which defines the indexes present + on all the system catalogs, and <code class="filename">toasting.h</code>, which + defines TOAST tables for catalogs that need one. + </p><p> + Many of the catalogs have initial data that must be loaded into them + during the <span class="quote">“<span class="quote">bootstrap</span>”</span> phase + of <span class="application">initdb</span>, to bring the system up to a point + where it is capable of executing SQL commands. (For + example, <code class="filename">pg_class.h</code> must contain an entry for itself, + as well as one for each other system catalog and index.) This + initial data is kept in editable form in data files that are also stored + in the <code class="filename">src/include/catalog/</code> directory. For example, + <code class="filename">pg_proc.dat</code> describes all the initial rows that must + be inserted into the <code class="structname">pg_proc</code> catalog. + </p><p> + To create the catalog files and load this initial data into them, a + backend running in bootstrap mode reads a <acronym class="acronym">BKI</acronym> + (Backend Interface) file containing commands and initial data. + The <code class="filename">postgres.bki</code> file used in this mode is prepared + from the aforementioned header and data files, while building + a <span class="productname">PostgreSQL</span> distribution, by a Perl script + named <code class="filename">genbki.pl</code>. + Although it's specific to a particular <span class="productname">PostgreSQL</span> + release, <code class="filename">postgres.bki</code> is platform-independent and is + installed in the <code class="filename">share</code> subdirectory of the + installation tree. + </p><p> + <code class="filename">genbki.pl</code> also produces a derived header file for + each catalog, for example <code class="filename">pg_class_d.h</code> for + the <code class="structname">pg_class</code> catalog. This file contains + automatically-generated macro definitions, and may contain other macros, + enum declarations, and so on that can be useful for client C code that + reads a particular catalog. + </p><p> + Most PostgreSQL developers don't need to be directly concerned with + the <acronym class="acronym">BKI</acronym> file, but almost any nontrivial feature + addition in the backend will require modifying the catalog header files + and/or initial data files. The rest of this chapter gives some + information about that, and for completeness describes + the <acronym class="acronym">BKI</acronym> file format. + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="storage-page-layout.html" title="69.6. Database Page Layout">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="internals.html" title="Part VII. Internals">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="system-catalog-declarations.html" title="70.1. System Catalog Declaration Rules">Next</a></td></tr><tr><td width="40%" align="left" valign="top">69.6. Database Page Layout </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 70.1. System Catalog Declaration Rules</td></tr></table></div></body></html>
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