PG_AM

OID

OID

-

Row identifier (hidden attribute; displayed only when explicitly selected).

amname

Name

-

Name of the access method.

amstrategies

Smallint

-

Number of operator strategies for this access method, or zero if access method does not have a fixed set of operator strategies.

amsupport

Smallint

-

Number of support routines for this access method.

amcanorder

boolean

-

Whether the access method supports ordered scans sorted by the indexed column's value.

amcanorderbyop

boolean

-

Whether the access method supports ordered scans sorted by the result of an operator on the indexed column.

amcanbackward

boolean

-

Whether the access method supports backward scanning.

amcanunique

boolean

-

Whether the access method supports unique indexes.

amcanmulticol

boolean

-

Whether the access method supports multi-column indexes.

amoptionalkey

boolean

-

Whether the access method supports a scan without any constraint for the first index column.

amsearcharray

boolean

-

Whether the access method supports ScalarArrayOpExpr searches.

amsearchnulls

boolean

-

Whether the access method supports IS NULL/NOT NULL searches.

amstorage

boolean

-

Whether an index storage data type can differ from a column data type.

amclusterable

boolean

-

Whether an index of this type can be clustered on.

ampredlocks

boolean

-

Whether an index of this type manages fine-grained predicate locks.

amkeytype

OID

PG_TYPE.oid

Type of data stored in index, or zero if not a fixed type.

aminsert

regproc

PG_PROC.oid

"Insert this tuple" function.

ambeginscan

regproc

PG_PROC.oid

"Prepare for index scan" function.

amgettuple

regproc

PG_PROC.oid

"Next valid tuple" function, or zero if none.

amgetbitmap

regproc

PG_PROC.oid

"Fetch all valid tuples" function, or zero if none.

amrescan

regproc

PG_PROC.oid

"(Re)start index scan" function.

amendscan

regproc

PG_PROC.oid

"Clean up after index scan" function.

ammarkpos

regproc

PG_PROC.oid

"Mark current scan position" function.

amrestrpos

regproc

PG_PROC.oid

"Restore marked scan position" function.

ammerge

regproc

PG_PROC.oid

"Merge multiple indexes" function.

ambuild

regproc

PG_PROC.oid

"Build new index" function.

ambuildempty

regproc

PG_PROC.oid

"Build empty index" function.

ambulkdelete

regproc

PG_PROC.oid

Bulk-delete function.

amvacuumcleanup

regproc

PG_PROC.oid

Post-VACUUM cleanup function.

amcanreturn

regproc

PG_PROC.oid

Function to check whether index supports index-only scans, or zero if none

amcostestimate

regproc

PG_PROC.oid

Function to estimate cost of an index scan.

amoptions

regproc

PG_PROC.oid

Function to parse and validate reloptions for an index.