diff options
Diffstat (limited to 'src/btree/row_srch.c')
| -rw-r--r-- | src/btree/row_srch.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/btree/row_srch.c b/src/btree/row_srch.c index 6169a0a810a..a631764be7e 100644 --- a/src/btree/row_srch.c +++ b/src/btree/row_srch.c @@ -634,6 +634,7 @@ __wt_row_random_leaf(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt) WT_INSERT *ins, **start, **stop; WT_INSERT_HEAD *ins_head; WT_PAGE *page; + uint64_t samples; uint32_t choice, entries, i; int level; @@ -688,7 +689,7 @@ __wt_row_random_leaf(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt) * Step down the skip list levels, selecting a random chunk of the name * space at each level. */ - while (level > 0) { + for (samples = entries; level > 0; samples += entries) { /* * There are (entries) or (entries + 1) chunks of the name space * considered at each level. They are: between start and the 1st @@ -765,6 +766,16 @@ __wt_row_random_leaf(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt) cbt->ins_head = ins_head; cbt->compare = 0; + /* + * Random lookups in newly created collections can be slow if a page + * consists of a large skiplist. Schedule the page for eviction if we + * encounter a large skiplist. This worthwhile because applications + * that take a sample often take many samples, so the overhead of + * traversing the skip list each time accumulates to real time. + */ + if (samples > 5000) + __wt_page_evict_soon(page); + return (0); } |