This release contains fixes from 7.4.16, including a security fix. For information about new features in the 7.4 major release, see Section E.153, « Release 7.4 ».
A dump/restore is not required for those running 7.4.X. However, if you are upgrading from a version earlier than 7.4.11, see Section E.142, « Release 7.4.11 ».
Support explicit placement of the temporary-table schema within search_path, and disable searching it for functions and operators (Tom)
This is needed to allow a security-definer function to set a truly secure value of search_path. Without it, an unprivileged SQL user can use temporary objects to execute code with the privileges of the security-definer function (CVE-2007-2138). See CREATE FUNCTION for more information.
/contrib/tsearch2 crash fixes (Teodor)
Fix potential-data-corruption bug in how VACUUM FULL handles UPDATE chains (Tom, Pavan Deolasee)
Fix PANIC during enlargement of a hash index (bug introduced in 7.4.15) (Tom)