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Include the backend ID in the relpath of temporary relations.

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This allows us to reliably remove all leftover temporary relation
files on cluster startup without reference to system catalogs or WAL;
therefore, we no longer include temporary relations in XLOG_XACT_COMMIT
and XLOG_XACT_ABORT WAL records.

Since these changes require including a backend ID in each
SharedInvalSmgrMsg, the size of the SharedInvalidationMessage.id
field has been reduced from two bytes to one, and the maximum number
of connections has been reduced from INT_MAX / 4 to 2^23-1.  It would
be possible to remove these restrictions by increasing the size of
SharedInvalidationMessage by 4 bytes, but right now that doesn't seem
like a good trade-off.

Review by Jaime Casanova and Tom Lane.
This commit is contained in:
Robert Haas
2010-08-13 20:10:54 +00:00
parent 3f9479ef3f
commit debcec7dc3
37 changed files with 669 additions and 343 deletions
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20
src/include/storage/sinval.h
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@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/sinval.h,v 1.59 2010/02/26 02:01:28 momjian Exp $
* $PostgreSQL: pgsql/src/include/storage/sinval.h,v 1.60 2010/08/13 20:10:53 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@@ -26,7 +26,7 @@
* * invalidate an smgr cache entry for a specific physical relation
* * invalidate the mapped-relation mapping for a given database
* More types could be added if needed. The message type is identified by
* the first "int16" field of the message struct. Zero or positive means a
* the first "int8" field of the message struct. Zero or positive means a
* specific-catcache inval message (and also serves as the catcache ID field).
* Negative values identify the other message types, as per codes below.
*
@@ -63,7 +63,7 @@
typedef struct
{
/* note: field layout chosen with an eye to alignment concerns */
int16 id; /* cache ID --- must be first */
int8 id; /* cache ID --- must be first */
ItemPointerData tuplePtr; /* tuple identifier in cached relation */
Oid dbId; /* database ID, or 0 if a shared relation */
uint32 hashValue; /* hash value of key for this catcache */
@@ -73,7 +73,7 @@ typedef struct
typedef struct
{
int16 id; /* type field --- must be first */
int8 id; /* type field --- must be first */
Oid dbId; /* database ID, or 0 if a shared catalog */
Oid catId; /* ID of catalog whose contents are invalid */
} SharedInvalCatalogMsg;
@@ -82,7 +82,7 @@ typedef struct
typedef struct
{
int16 id; /* type field --- must be first */
int8 id; /* type field --- must be first */
Oid dbId; /* database ID, or 0 if a shared relation */
Oid relId; /* relation ID */
} SharedInvalRelcacheMsg;
@@ -91,21 +91,23 @@ typedef struct
typedef struct
{
int16 id; /* type field --- must be first */
RelFileNode rnode; /* physical file ID */
int8 id; /* type field --- must be first */
int8 backend_hi; /* high bits of backend ID, if temprel */
uint16 backend_lo; /* low bits of backend ID, if temprel */
RelFileNode rnode; /* spcNode, dbNode, relNode */
} SharedInvalSmgrMsg;
#define SHAREDINVALRELMAP_ID (-4)
typedef struct
{
int16 id; /* type field --- must be first */
int8 id; /* type field --- must be first */
Oid dbId; /* database ID, or 0 for shared catalogs */
} SharedInvalRelmapMsg;
typedef union
{
int16 id; /* type field --- must be first */
int8 id; /* type field --- must be first */
SharedInvalCatcacheMsg cc;
SharedInvalCatalogMsg cat;
SharedInvalRelcacheMsg rc;