index 3de9f39d3252ac0eba3763a91da842ddbbe094a9..5e23fe13d7bc5dce9241f8841602b07c9735a9ed 100644 (file)
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/nbtree/Attic/nbtscan.c,v 1.6 1996年11月15日 18:37:00 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/Attic/nbtscan.c,v 1.7 1997年02月18日 17:13:45 momjian Exp $
*
*
* NOTES
typedef BTScanListData *BTScanList;
static BTScanList BTScans = (BTScanList) NULL;
-
+
+static void _bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno);
+static bool _bt_scantouched(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno);
+
/*
* _bt_regscan() -- register a new scan.
*/
pfree (chk);
}
+/*
+ * _bt_adjscans() -- adjust all scans in the scan list to compensate
+ * for a given deletion or insertion
+ */
void
-_bt_adjscans(Relation rel, ItemPointer tid)
+_bt_adjscans(Relation rel, ItemPointer tid, int op)
{
BTScanList l;
Oid relid;
@@ -90,13 +97,34 @@ _bt_adjscans(Relation rel, ItemPointer tid)
relid = rel->rd_id;
for (l = BTScans; l != (BTScanList) NULL; l = l->btsl_next) {
if (relid == l->btsl_scan->relation->rd_id)
- _bt_scandel(l->btsl_scan, ItemPointerGetBlockNumber(tid),
+ _bt_scandel(l->btsl_scan, op,
+ ItemPointerGetBlockNumber(tid),
ItemPointerGetOffsetNumber(tid));
}
}
-void
-_bt_scandel(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno)
+/*
+ * _bt_scandel() -- adjust a single scan
+ *
+ * because each index page is always maintained as an ordered array of
+ * index tuples, the index tuples on a given page shift beneath any
+ * given scan. an index modification "behind" a scan position (i.e.,
+ * same page, lower or equal offset number) will therefore force us to
+ * adjust the scan in the following ways:
+ *
+ * - on insertion, we shift the scan forward by one item.
+ * - on deletion, we shift the scan backward by one item.
+ *
+ * note that:
+ *
+ * - we need not worry about the actual ScanDirection of the scan
+ * itself, since the problem is that the "current" scan position has
+ * shifted.
+ * - modifications "ahead" of our scan position do not change the
+ * array index of the current scan position and so can be ignored.
+ */
+static void
+_bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno)
{
ItemPointer current;
Buffer buf;
@@ -112,7 +140,17 @@ _bt_scandel(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno)
if (ItemPointerIsValid(current)
&& ItemPointerGetBlockNumber(current) == blkno
&& ItemPointerGetOffsetNumber(current) >= offno) {
- _bt_step(scan, &buf, BackwardScanDirection);
+ switch (op) {
+ case BT_INSERT:
+ _bt_step(scan, &buf, ForwardScanDirection);
+ break;
+ case BT_DELETE:
+ _bt_step(scan, &buf, BackwardScanDirection);
+ break;
+ default:
+ elog(WARN, "_bt_scandel: bad operation '%d'", op);
+ /*NOTREACHED*/
+ }
so->btso_curbuf = buf;
}
@@ -124,7 +162,17 @@ _bt_scandel(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno)
tmp = *current;
*current = scan->currentItemData;
scan->currentItemData = tmp;
- _bt_step(scan, &buf, BackwardScanDirection);
+ switch (op) {
+ case BT_INSERT:
+ _bt_step(scan, &buf, ForwardScanDirection);
+ break;
+ case BT_DELETE:
+ _bt_step(scan, &buf, BackwardScanDirection);
+ break;
+ default:
+ elog(WARN, "_bt_scandel: bad operation '%d'", op);
+ /*NOTREACHED*/
+ }
so->btso_mrkbuf = buf;
tmp = *current;
*current = scan->currentItemData;
@@ -132,7 +180,11 @@ _bt_scandel(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno)
}
}
-bool
+/*
+ * _bt_scantouched() -- check to see if a scan is affected by a given
+ * change to the index
+ */
+static bool
_bt_scantouched(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno)
{
ItemPointer current;
index 1cb91dcaa7eac2a37fa8bd2daf5de72d58235a1a..bbbd02b0644819ec6b58c40f2200100ef7ca3f38 100644 (file)
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.40 1997年02月14日 04:16:12 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.41 1997年02月18日 17:13:58 momjian Exp $
*
* NOTES
*
else
DebugLvl = 1;
break;
- case 'e':
- /*
- * Use european date formats.
- */
- EuroDates = 1;
- break;
case 'm':
MultiplexedBackends = 1;
MultiplexedBackendPort = atoi(optarg);
fprintf(stderr, "\t-b backend\tuse a specific backend server executable\n");
fprintf(stderr, "\t-d [1|2|3]\tset debugging level\n");
fprintf(stderr, "\t-D datadir\tset data directory\n");
- fprintf(stderr, "\t-e \tturn on European date format\n");
fprintf(stderr, "\t-m \tstart up multiplexing backends\n");
fprintf(stderr, "\t-n\t\tdon't reinitialize shared memory after abnormal exit\n");
fprintf(stderr, "\t-o option\tpass 'option' to each backend servers\n");
av[ac++] = "-o";
av[ac++] = ttybuf;
}
-
- /* tell the backend we're using European dates */
- if (EuroDates == 1)
- av[ac++] = "-e";
/* tell the multiplexed backend to start on a certain port */
if (MultiplexedBackends) {
index 1ba24d044b52c18b19167a3714acdf6bd83695e1..c1a857bb74a05353303b444ecc2536e41a376b04 100644 (file)
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: nbtree.h,v 1.7 1997年02月14日 22:47:36 momjian Exp $
+ * $Id: nbtree.h,v 1.8 1997年02月18日 17:14:10 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -238,9 +238,7 @@ extern void btdelete(Relation rel, ItemPointer tid);
*/
extern void _bt_regscan(IndexScanDesc scan);
extern void _bt_dropscan(IndexScanDesc scan);
-extern void _bt_adjscans(Relation rel, ItemPointer tid);
-extern void _bt_scandel(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno);
-extern bool _bt_scantouched(IndexScanDesc scan, BlockNumber blkno, OffsetNumber offno);
+extern void _bt_adjscans(Relation rel, ItemPointer tid, int op);
/*
* prototypes for functions in nbtsearch.c
index 3ee1f457c2e6cf91f3340742af50968be743984e..08cc9fa763f638697ea5b6498e3b91b62e35b10e 100644 (file)
.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
-.\" $Header: /cvsroot/pgsql/src/man/Attic/postmaster.1,v 1.3 1997年01月26日 15:32:28 scrappy Exp $
+.\" $Header: /cvsroot/pgsql/src/man/Attic/postmaster.1,v 1.4 1997年02月18日 17:14:25 momjian Exp $
.TH POSTMASTER UNIX 11/05/95 PostgreSQL PostgreSQL
.SH "NAME"
postmaster \(em run the Postgres postmaster
.IR shmemdoc
program to examine shared memory and semaphore state.
.TP
-.BR "-e"
-The
-.IR "-e"
-option controls how dates are input to and output from the database.
-.IP
-If the
-.IR "-e"
-option is supplied, then all dates passed to and from the frontend
-processes will be assumed to be in
-.IR "European"
-format ie.
-.IR "DD-MM-YYYY"
-otherwise dates are input and output in
-.IR "American"
-format ie.
-.IR "MM-DD-YYYY"
-.TP
.BR "-o" " backend_options"
The
.IR postgres (1)