ANSI vs. Non-ANSI Databases

Hi, What is the difference between an ANSI-compliant and not-ANSI-compliant database? Does this term relate only to Informix OnLine? -- Azarkar.

Ali Azarkar wrote: > > Hi, > What is the difference between an ANSI-compliant and not-ANSI-compliant > database? Does this term relate only to Informix OnLine? This refers to logging and transaction handling requirements that ANSI imposes on compliant databases. Informix is one of the few vendors which provides an ANSI compliance option. It is implemented as a logging mode of the database. When creating the database add the clause "WITH LOG MODE ANSI". To alter a database from another logging mode to ANSI mode you have to take a level 0 archive of the system and add the flag: "-A <database list>" to ontape. OnBar has an equivalent option (see the Backup and Restore manual). Details? ANSI mode databases begin and implied transaction with the first SQL statement which is not part of an existing transaction. Such a transaction continues until it is either commited or rolled back. This differs from BUFFERED and UNBUFFERED logging modes in that it is illegal (and unneccessary) to issue a BEGIN WORK statement and you cannot have any statements that constitute singleton transaction under ANSI logging mode. In addition, ANSI mode is an UNBUFFERED logging mode which adds some subtle differences from Informix UNBUFFERED logging mode. See the Administrator's Guide for details on this point. Lastly, ANSI also specifies the default, and possible, ISOLATION LEVELS for a compliant database which differs from the default ISOLATION for Informix logging mode (and unlogged) databases. Again see the Admin Guide for details. Art S. Kagel