| commit | db22f1189181e47c36e0cfe4ee80c88bb1e75944 | |
| author | tgl <tgl> | |
| Tue, 24 Mar 2009 22:06:03 +0000 (24 22:06 +0000) | ||
| committer | tgl <tgl> | |
| Tue, 24 Mar 2009 22:06:03 +0000 (24 22:06 +0000) | ||
| tree | 5608efbf355772d5fec8d0bb9afb5d2fce2fd198 | treesnapshot (tar.gz zip) |
| parent | fc6d1def728b9a2a8ce7e7423af6d08621b53391 | commitdiff |
Install a search tree depth limit in GIN bulk-insert operations, to prevent
them from degrading badly when the input is sorted or nearly so. In this
scenario the tree is unbalanced to the point of becoming a mere linked list,
so insertions become O(N^2). The easiest and most safely back-patchable
solution is to stop growing the tree sooner, ie limit the growth of N. We
might later consider a rebalancing tree algorithm, but it's not clear that
the benefit would be worth the cost and complexity. Per report from Sergey
Burladyan and an earlier complaint from Heikki.
Back-patch to 8.2; older versions didn't have GIN indexes.
them from degrading badly when the input is sorted or nearly so. In this
scenario the tree is unbalanced to the point of becoming a mere linked list,
so insertions become O(N^2). The easiest and most safely back-patchable
solution is to stop growing the tree sooner, ie limit the growth of N. We
might later consider a rebalancing tree algorithm, but it's not clear that
the benefit would be worth the cost and complexity. Per report from Sergey
Burladyan and an earlier complaint from Heikki.
Back-patch to 8.2; older versions didn't have GIN indexes.
| src/backend/access/gin/ginfast.c | diffblobblamehistory | |
| src/backend/access/gin/gininsert.c | diffblobblamehistory | |
| src/include/access/gin.h | diffblobblamehistory |