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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2006-09-15 16:39:32 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2006-09-15 16:39:32 +0000 |
| commit | 0498a08e6619be6803025e40e19892df4dffb0bc (patch) | |
| tree | 9a7ae6bee222aea06f2b9b6a5d50ceeccc9cb431 | |
| parent | fa6f9ceab646c9b3f1c582eef7adbc0bce10e0e9 (diff) | |
| download | postgresql-0498a08e6619be6803025e40e19892df4dffb0bc.tar.gz postgresql-0498a08e6619be6803025e40e19892df4dffb0bc.zip | |
Improve confusing comment for HeapTupleSatisfiesNow, per gripe from Greg Stark.
| -rw-r--r-- | src/backend/utils/time/tqual.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c index 5a19e12553d..a3b52fa7eb4 100644 --- a/src/backend/utils/time/tqual.c +++ b/src/backend/utils/time/tqual.c @@ -32,7 +32,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.96 2006/09/03 15:59:39 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.97 2006/09/15 16:39:32 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -253,19 +253,18 @@ HeapTupleSatisfiesItself(HeapTupleHeader tuple, Buffer buffer) * * The satisfaction of "now" requires the following: * - * ((Xmin == my-transaction && changed by the current transaction - * Cmin != my-command && but not by this command, and - * (Xmax is null || the row has not been deleted, or - * (Xmax == my-transaction && it was deleted by the current transaction - * Cmax != my-command))) but not by this command, + * ((Xmin == my-transaction && inserted by the current transaction + * Cmin < my-command && before this command, and + * (Xmax is null || the row has not been deleted, or + * (Xmax == my-transaction && it was deleted by the current transaction + * Cmax >= my-command))) but not before this command, * || or - * - * (Xmin is committed && the row was modified by a committed transaction, and + * (Xmin is committed && the row was inserted by a committed transaction, and * (Xmax is null || the row has not been deleted, or - * (Xmax == my-transaction && the row is being deleted by this command, or - * Cmax == my-command) || - * (Xmax is not committed && the row was deleted by another transaction - * Xmax != my-transaction)))) that has not been committed + * (Xmax == my-transaction && the row is being deleted by this transaction + * Cmax >= my-command) || but it's not deleted "yet", or + * (Xmax != my-transaction && the row was deleted by another transaction + * Xmax is not committed)))) that has not been committed * * mao says 17 march 1993: the tests in this routine are correct; * if you think they're not, you're wrong, and you should think |