tested on:
1. 9.1.3
2. 9.3devel (yesterdays head in git)
steps to reproduce:
$ create table z (i int4);
CREATE TABLE
$ create unique index q on z (i);
CREATE INDEX
$ alter table z add primary key using index q;
ALTER TABLE
$ alter table z alter column i type int8;
ERROR: could not open relation with OID 16503
looks like some missing dependancy.
Best regards,
depesz
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