diff options
Diffstat (limited to 'src/backend/commands')
| -rw-r--r-- | src/backend/commands/async.c | 11 | ||||
| -rw-r--r-- | src/backend/commands/vacuum.c | 10 |
2 files changed, 9 insertions, 12 deletions
diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c index 4c1286eb988..774b26fd2c4 100644 --- a/src/backend/commands/async.c +++ b/src/backend/commands/async.c @@ -302,13 +302,10 @@ static SlruCtlData NotifyCtlData; #define QUEUE_FULL_WARN_INTERVAL 5000 /* warn at most once every 5s */ /* - * slru.c currently assumes that all filenames are four characters of hex - * digits. That means that we can use segments 0000 through FFFF. - * Each segment contains SLRU_PAGES_PER_SEGMENT pages which gives us - * the pages from 0 to SLRU_PAGES_PER_SEGMENT * 0x10000 - 1. - * - * It's of course possible to enhance slru.c, but this gives us so much - * space already that it doesn't seem worth the trouble. + * Use segments 0000 through FFFF. Each contains SLRU_PAGES_PER_SEGMENT pages + * which gives us the pages from 0 to SLRU_PAGES_PER_SEGMENT * 0x10000 - 1. + * We could use as many segments as SlruScanDirectory() allows, but this gives + * us so much space already that it doesn't seem worth the trouble. * * The most data we can have in the queue at a time is QUEUE_MAX_PAGE/2 * pages, because more than that would confuse slru.c into thinking there diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index 5189a5ad5e3..23eb605d4cb 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -949,11 +949,11 @@ vacuum_set_xid_limits(Relation rel, /* * We can always ignore processes running lazy vacuum. This is because we * use these values only for deciding which tuples we must keep in the - * tables. Since lazy vacuum doesn't write its XID anywhere, it's safe to - * ignore it. In theory it could be problematic to ignore lazy vacuums in - * a full vacuum, but keep in mind that only one vacuum process can be - * working on a particular table at any time, and that each vacuum is - * always an independent transaction. + * tables. Since lazy vacuum doesn't write its XID anywhere (usually no + * XID assigned), it's safe to ignore it. In theory it could be + * problematic to ignore lazy vacuums in a full vacuum, but keep in mind + * that only one vacuum process can be working on a particular table at + * any time, and that each vacuum is always an independent transaction. */ *oldestXmin = GetOldestNonRemovableTransactionId(rel); |