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| author | Michael Cahill <michael.cahill@wiredtiger.com> | 2013-05-15 15:53:52 +1000 |
|---|---|---|
| committer | Michael Cahill <michael.cahill@wiredtiger.com> | 2013-05-15 15:53:52 +1000 |
| commit | 4e73800d4f502870ba42bb5887b3b0bcb87f24e0 (patch) | |
| tree | 39649df07efb7926b4b1160788c8e16a4c246867 /src | |
| parent | dc84be5ab9ef9c30d04fd8043f297df5d020cb04 (diff) | |
| download | mongo-4e73800d4f502870ba42bb5887b3b0bcb87f24e0.tar.gz | |
Add a comment about tracking the largest transaction ID during reconciliation.
Diffstat (limited to 'src')
| -rw-r--r-- | src/btree/rec_write.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/btree/rec_write.c b/src/btree/rec_write.c index edbdacde7b7..37af35e79cd 100644 --- a/src/btree/rec_write.c +++ b/src/btree/rec_write.c @@ -604,6 +604,13 @@ __rec_txn_read( *updp = __wt_txn_read_skip(session, upd, &skip); if (!skip) { + /* + * Track the largest transaction ID written to disk for this + * page. We store this in the page at the end of + * reconciliation if no updates are skipped. It is used to + * avoid evicting a clean page from memory with changes that + * are required to satisfy a snapshot read. + */ if (*updp != NULL) { txnid = (*updp)->txnid; if (TXNID_LT(r->max_txn, txnid)) |