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7 | 7 | * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group |
8 | 8 | * Portions Copyright (c) 1994, Regents of the University of California |
9 | 9 | * |
10 | | - * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.432 2010/08/26 19:23:41 alvherre Exp $ |
| 10 | + * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.433 2010/08/30 14:22:05 sriggs Exp $ |
11 | 11 | * |
12 | 12 | *------------------------------------------------------------------------- |
13 | 13 | */ |
@@ -7706,10 +7706,14 @@ CreateRestartPoint(int flags) |
7706 | 7706 | } |
7707 | 7707 |
|
7708 | 7708 | /* |
7709 | | - * Currently, there is no need to truncate pg_subtrans during recovery. If |
7710 | | - * we did do that, we will need to have called StartupSUBTRANS() already |
7711 | | - * and then TruncateSUBTRANS() would go here. |
| 7709 | + * Truncate pg_subtrans if possible. We can throw away all data before |
| 7710 | + * the oldest XMIN of any running transaction.No future transaction will |
| 7711 | + * attempt to reference any pg_subtrans entry older than that (see Asserts |
| 7712 | + * in subtrans.c).When hot standby is disabled, though, we mustn't do |
| 7713 | + * this because StartupSUBTRANS hasn't been called yet. |
7712 | 7714 | */ |
| 7715 | +if (EnableHotStandby) |
| 7716 | +TruncateSUBTRANS(GetOldestXmin(true, false)); |
7713 | 7717 |
|
7714 | 7718 | /* All real work is done, but log before releasing lock. */ |
7715 | 7719 | if (log_checkpoints) |
|