41 lines
1.8 KiB
Plaintext
41 lines
1.8 KiB
Plaintext
# $Header: /cvsroot/pgsql/src/backend/storage/smgr/README,v 1.1.1.1 1996/07/09 06:21:59 scrappy Exp $
|
|
|
|
This directory contains the code that supports the Postgres storage manager
|
|
switch and all of the installed storage managers. In released systems,
|
|
the only supported storage manager is the magnetic disk manager. At UC
|
|
Berkeley, the Sony WORM optical disk jukebox and persistent main memory are
|
|
also supported.
|
|
|
|
As of Postgres Release 3.0, every relation in the system is tagged with the
|
|
storage manager on which it resides. The storage manager switch code turns
|
|
what used to by filesystem operations into operations on the correct store,
|
|
for any given relation.
|
|
|
|
The files in this directory, and their contents, are
|
|
|
|
smgrtype.c Storage manager type -- maps string names to storage manager
|
|
IDs and provides simple comparison operators. This is the
|
|
regproc support for type 'smgr' in the system catalogs.
|
|
|
|
smgr.c The storage manager switch dispatch code. The routines in
|
|
this file call the appropriate storage manager to do hardware
|
|
accesses requested by the backend.
|
|
|
|
md.c The magnetic disk storage manager.
|
|
|
|
mm.c The persistent main memory storage manager (#undef'ed in
|
|
tmp/c.h for all distributed systems).
|
|
|
|
sj.c The sony jukebox storage manager and cache management code
|
|
(#undef'ed in tmp/c.h for all distributed systems). The
|
|
routines in this file allocate extents, maintain block
|
|
maps, and guarantee the persistence and coherency of a cache
|
|
of jukebox blocks on magnetic disk.
|
|
|
|
pgjb.c The postgres jukebox interface routines. The routines here
|
|
handle exclusion on the physical device and translate requests
|
|
from the storage manager code (sj.c) into jbaccess calls.
|
|
|
|
jbaccess.c Access code for the physical Sony jukebox device. This code
|
|
was swiped from Andy McFadden's jblib.a code at UC Berkeley.
|