This release contains a variety of fixes from 7.4.27. For information about new features in the 7.4 major release, see Section E.173, « Sortie 7.4 ».
The PostgreSQL™ community will stop releasing updates for the 7.4.X release series in July 2010. Users are encouraged to update to a newer release branch soon.
A dump/restore is not required for those running 7.4.X. However, if you are upgrading from a version earlier than 7.4.26, see the release notes for 7.4.26.
Add new configuration parameter ssl_renegotiation_limit to control how often we do session key renegotiation for an SSL connection (Magnus)
This can be set to zero to disable renegotiation completely, which may be required if a broken SSL library is used. In particular, some vendors are shipping stopgap patches for CVE-2009-3555 that cause renegotiation attempts to fail.
Make substring() for bit types treat any negative length as meaning « all the rest of the string » (Tom)
The previous coding treated only -1 that way, and would produce an invalid result value for other negative values, possibly leading to a crash (CVE-2010-0442).
Fix some cases of pathologically slow regular expression matching (Tom)
When reading pg_hba.conf and related files, do not treat @something as a file inclusion request if the @ appears inside quote marks; also, never treat @ by itself as a file inclusion request (Tom)
This prevents erratic behavior if a role or database name starts with @. If you need to include a file whose path name contains spaces, you can still do so, but you must write @"/path to/file" rather than putting the quotes around the whole construct.
Prevent infinite loop on some platforms if a directory is named as an inclusion target in pg_hba.conf and related files (Tom)
Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
The only known symptom of this oversight is that the Tcl clock command misbehaves if using Tcl 8.5 or later.
Prevent crash in contrib/dblink when too many key columns are specified to a dblink_build_sql_* function (Rushabh Lathia, Joe Conway)