Hackers,
During the version 14 development period, a few checks of toasted attributes were written but never committed. For the
version15 development cycle, I'd like to consider extending the checks of toasted attributes. First, no toasted
attributeshould ever have a rawsize larger than the 1GB varlena limit. Second, no compressed toasted attribute should
havean extsize indicating that the toast expanded during toasting. Such a extsize could mean the compression code is
malfunctioning,or that the extsize or rawsize fields are corrupt. Third, any compressed attribute should have a valid
compressionmethod ID.
These checks are cheap. Actually retrieving the compressed toasted data and checking that it uncompresses correctly
wouldhave very different performance implications, but that is not included in this patch.
—
Mark Dilger
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company