diff options
| author | Michael Paquier | 2021-06-14 05:57:22 +0000 |
|---|---|---|
| committer | Michael Paquier | 2021-06-14 05:57:22 +0000 |
| commit | 2d689babe3cb50dcb29f6ed595a61d56e518c0d8 (patch) | |
| tree | 49069eccb9bbdfc801b5b27e5a23b3e55ab12bce /src/backend/commands/event_trigger.c | |
| parent | dbab0c07e5ba1f19a991da2d72972a8fe9a41bda (diff) | |
Improve handling of dropped objects in pg_event_trigger_ddl_commands()
An object found as dropped when digging into the list of objects
returned by pg_event_trigger_ddl_commands() could cause a cache lookup
error, as the calls grabbing for the object address and the type name
would fail if the object was missing.
Those lookup errors could be seen with combinations of ALTER TABLE
sub-commands involving identity columns. The lookup logic is changed in
this code path to get a behavior similar to any other SQL-callable
function by ignoring objects that are not found, taking advantage of
2a10fdc. The back-branches are not changed, as they require this commit
that is too invasive for stable branches.
While on it, add test cases to exercise event triggers with identity
columns, and stress more cases with the event ddl_command_end for
relations.
Author: Sven Klemm, Aleksander Alekseev, Michael Paquier
Discussion: https://postgr.es/m/CAMCrgp2R1cEXU53iYKtW6yVEp2_yKUz+z=3-CTrYpPP+xryRtg@mail.gmail.com
Diffstat (limited to 'src/backend/commands/event_trigger.c')
| -rw-r--r-- | src/backend/commands/event_trigger.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c index 5bde507c752..9c31c9e7637 100644 --- a/src/backend/commands/event_trigger.c +++ b/src/backend/commands/event_trigger.c @@ -1936,8 +1936,19 @@ pg_event_trigger_ddl_commands(PG_FUNCTION_ARGS) else if (cmd->type == SCT_AlterTSConfig) addr = cmd->d.atscfg.address; - type = getObjectTypeDescription(&addr, false); - identity = getObjectIdentity(&addr, false); + /* + * If an object was dropped in the same command we may end + * up in a situation where we generated a message but can + * no longer look for the object information, so skip it + * rather than failing. This can happen for example with + * some subcommand combinations of ALTER TABLE. + */ + identity = getObjectIdentity(&addr, true); + if (identity == NULL) + continue; + + /* The type can never be NULL. */ + type = getObjectTypeDescription(&addr, true); /* * Obtain schema name, if any ("pg_temp" if a temp |