Обсуждение: pgsql: Fix nasty bug in nodeIndexscan.c's detection of duplicate tuples
pgsql: Fix nasty bug in nodeIndexscan.c's detection of duplicate tuples
От
tgl@postgresql.org (Tom Lane)
Дата:
Log Message: ----------- Fix nasty bug in nodeIndexscan.c's detection of duplicate tuples during a multiple (OR'ed) indexscan. It was checking for duplicate tuple->t_data->t_ctid, when what it should be checking is tuple->t_self. The trouble situation occurs when a live tuple has t_ctid not pointing to itself, which can happen if an attempted UPDATE was rolled back. After a VACUUM, an unrelated tuple could be installed where the failed update tuple was, leading to one live tuple's t_ctid pointing to an unrelated tuple. If one of these tuples is fetched by an earlier OR'ed indexscan and the other by a later indexscan, nodeIndexscan.c would incorrectly ignore the second tuple. The bug exists in all 7.4.* and 8.0.* versions, but not in earlier or later branches because this code was only used in those releases. Per trouble report from Rafael Martinez Guerrero. Tags: ---- REL7_4_STABLE Modified Files: -------------- pgsql/src/backend/executor: nodeIndexscan.c (r1.84.2.1 -> r1.84.2.2) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeIndexscan.c.diff?r1=1.84.2.1&r2=1.84.2.2)