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| -rw-r--r-- | doc/src/sgml/glossary.sgml | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml index 7c01a541fe4..29bf1873bdc 100644 --- a/doc/src/sgml/glossary.sgml +++ b/doc/src/sgml/glossary.sgml @@ -252,6 +252,34 @@ </glossdef> </glossentry> + <glossentry id="glossary-buffer-access-strategy"> + <glossterm>Buffer Access Strategy</glossterm> + <glossdef> + <para> + Some operations will access a large number of + <glossterm linkend="glossary-data-page">pages</glossterm>. A + <firstterm>Buffer Access Strategy</firstterm> helps to prevent these + operations from evicting too many pages from + <glossterm linkend="glossary-shared-memory">shared buffers</glossterm>. + </para> + <para> + A Buffer Access Strategy sets up references to a limited number of + <glossterm linkend="glossary-shared-memory">shared buffers</glossterm> and + reuses them circularly. When the operation requires a new page, a victim + buffer is chosen from the buffers in the strategy ring, which may require + flushing the page's dirty data and possibly also unflushed + <glossterm linkend="glossary-wal">WAL</glossterm> to permanent storage. + </para> + <para> + Buffer Access Strategies are used for various operations such as + sequential scans of large tables, <command>VACUUM</command>, + <command>COPY</command>, <command>CREATE TABLE AS SELECT</command>, + <command>ALTER TABLE</command>, <command>CREATE DATABASE</command>, + <command>CREATE INDEX</command>, and <command>CLUSTER</command>. + </para> + </glossdef> + </glossentry> + <glossentry id="glossary-cast"> <glossterm>Cast</glossterm> <glossdef> |