diff options
Diffstat (limited to 'src/backend/access/heap/pruneheap.c')
| -rw-r--r-- | src/backend/access/heap/pruneheap.c | 57 |
1 files changed, 28 insertions, 29 deletions
diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c index 4b445c7ad8..71ea689d0e 100644 --- a/src/backend/access/heap/pruneheap.c +++ b/src/backend/access/heap/pruneheap.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/heap/pruneheap.c,v 1.17 2009/01/01 17:23:35 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/access/heap/pruneheap.c,v 1.18 2009/06/11 14:48:53 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -30,7 +30,7 @@ typedef struct { TransactionId new_prune_xid; /* new prune hint value for page */ - int nredirected; /* numbers of entries in arrays below */ + int nredirected; /* numbers of entries in arrays below */ int ndead; int nunused; /* arrays that accumulate indexes of items to be changed */ @@ -159,21 +159,21 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin, /* * Our strategy is to scan the page and make lists of items to change, - * then apply the changes within a critical section. This keeps as - * much logic as possible out of the critical section, and also ensures - * that WAL replay will work the same as the normal case. + * then apply the changes within a critical section. This keeps as much + * logic as possible out of the critical section, and also ensures that + * WAL replay will work the same as the normal case. * - * First, inform inval.c that upcoming CacheInvalidateHeapTuple calls - * are nontransactional. + * First, inform inval.c that upcoming CacheInvalidateHeapTuple calls are + * nontransactional. */ if (redirect_move) BeginNonTransactionalInvalidation(); /* - * Initialize the new pd_prune_xid value to zero (indicating no - * prunable tuples). If we find any tuples which may soon become - * prunable, we will save the lowest relevant XID in new_prune_xid. - * Also initialize the rest of our working state. + * Initialize the new pd_prune_xid value to zero (indicating no prunable + * tuples). If we find any tuples which may soon become prunable, we will + * save the lowest relevant XID in new_prune_xid. Also initialize the rest + * of our working state. */ prstate.new_prune_xid = InvalidTransactionId; prstate.nredirected = prstate.ndead = prstate.nunused = 0; @@ -204,9 +204,9 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin, } /* - * Send invalidation messages for any tuples we are about to move. - * It is safe to do this now, even though we could theoretically still - * fail before making the actual page update, because a useless cache + * Send invalidation messages for any tuples we are about to move. It is + * safe to do this now, even though we could theoretically still fail + * before making the actual page update, because a useless cache * invalidation doesn't hurt anything. Also, no one else can reload the * tuples while we have exclusive buffer lock, so it's not too early to * send the invals. This avoids sending the invals while inside the @@ -222,9 +222,8 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin, if (prstate.nredirected > 0 || prstate.ndead > 0 || prstate.nunused > 0) { /* - * Apply the planned item changes, then repair page fragmentation, - * and update the page's hint bit about whether it has free line - * pointers. + * Apply the planned item changes, then repair page fragmentation, and + * update the page's hint bit about whether it has free line pointers. */ heap_page_prune_execute(buffer, prstate.redirected, prstate.nredirected, @@ -268,8 +267,8 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin, { /* * If we didn't prune anything, but have found a new value for the - * pd_prune_xid field, update it and mark the buffer dirty. - * This is treated as a non-WAL-logged hint. + * pd_prune_xid field, update it and mark the buffer dirty. This is + * treated as a non-WAL-logged hint. * * Also clear the "page is full" flag if it is set, since there's no * point in repeating the prune/defrag process until something else @@ -334,8 +333,8 @@ heap_page_prune(Relation relation, Buffer buffer, TransactionId OldestXmin, * OldestXmin is the cutoff XID used to identify dead tuples. * * We don't actually change the page here, except perhaps for hint-bit updates - * caused by HeapTupleSatisfiesVacuum. We just add entries to the arrays in - * prstate showing the changes to be made. Items to be redirected are added + * caused by HeapTupleSatisfiesVacuum. We just add entries to the arrays in + * prstate showing the changes to be made. Items to be redirected are added * to the redirected[] array (two entries per redirection); items to be set to * LP_DEAD state are added to nowdead[]; and items to be set to LP_UNUSED * state are added to nowunused[]. @@ -598,19 +597,19 @@ heap_prune_chain(Relation relation, Buffer buffer, OffsetNumber rootoffnum, else if (redirect_move && ItemIdIsRedirected(rootlp)) { /* - * If we desire to eliminate LP_REDIRECT items by moving tuples, - * make a redirection entry for each redirected root item; this - * will cause heap_page_prune_execute to actually do the move. - * (We get here only when there are no DEAD tuples in the chain; - * otherwise the redirection entry was made above.) + * If we desire to eliminate LP_REDIRECT items by moving tuples, make + * a redirection entry for each redirected root item; this will cause + * heap_page_prune_execute to actually do the move. (We get here only + * when there are no DEAD tuples in the chain; otherwise the + * redirection entry was made above.) */ heap_prune_record_redirect(prstate, rootoffnum, chainitems[1]); redirect_target = chainitems[1]; } /* - * If we are going to implement a redirect by moving tuples, we have - * to issue a cache invalidation against the redirection target tuple, + * If we are going to implement a redirect by moving tuples, we have to + * issue a cache invalidation against the redirection target tuple, * because its CTID will be effectively changed by the move. Note that * CacheInvalidateHeapTuple only queues the request, it doesn't send it; * if we fail before reaching EndNonTransactionalInvalidation, nothing @@ -693,7 +692,7 @@ heap_prune_record_unused(PruneState *prstate, OffsetNumber offnum) * buffer, and is inside a critical section. * * This is split out because it is also used by heap_xlog_clean() - * to replay the WAL record when needed after a crash. Note that the + * to replay the WAL record when needed after a crash. Note that the * arguments are identical to those of log_heap_clean(). */ void |