52.3. pg

52.3. `pg_am`
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52.3. `pg_am` #

The catalog pg_am stores information about relation access methods. There is one row for each access method supported by the system. Currently, only tables and indexes have access methods. The requirements for table and index access methods are discussed in detail in Chapter 62 and Chapter 63 respectively.

Table 52.3. pg_am Columns

Tipo y columna Descripción
`oid` `oid` Identificador de fila
`amname` `name` Nombre del método de acceso
`amhandler` `regproc` (hace referencia a `pg_proc`.`oid`) OID of a handler function that is responsible for supplying information about the access method
`amtype` `char` `t` = table (including materialized views), `i` = index.

Tipo y columna

Descripción

oid oid

Identificador de fila

amname name

Nombre del método de acceso

amhandler regproc (hace referencia a pg_proc.oid)

OID of a handler function that is responsible for supplying information about the access method

amtype char

t = table (including materialized views), i = index.

Note

Before PostgreSQL 9.6, pg_am contained many additional columns representing properties of index access methods. That data is now only directly visible at the C code level. However, pg_index_column_has_property() and related functions have been added to allow SQL queries to inspect index access method properties; see Table 9.76.

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52.3. pg_am #

Note

52.3. `pg_am` #