Used by two-phase commit applications to see if a server is prepared to commit a transaction.
prepare tran[saction]
Usage
When the Distributed Transaction Manager (DTM) is enabled, DTM handles all transaction processing for servers of server class ASEnterprise with a version of 12.0 or later.
prepare transaction is ignored for servers with a server class of db2.
For all other server classes, Adaptive Server notifies Component Integration Services when it receives a prepare transaction command so that remote servers involved in the current transaction can enter the prepared state.
For each server that is involved in the current transaction, a prepare transaction command is sent to the server and the results are monitored. If there are no errors reported, each remote server is assumed to be in a prepared state and Component Integration Services returns control to the Adaptive Server. Adaptive Server then enters a prepared state for local work performed by the transaction.
Transaction process for servers in class ASEnterprise with a version prior to 12.0 is identical to that of server class sql_server (release 10.0 or later).
When DTM is not enabled, transaction processing for all servers in class ASEnterprise is identical to that of server class sql_server (release 10.0 or later).
When the Adaptive Server receives notification to prepare a transaction, the Distributed Transaction Manager issues a PrepareXact RPC to all remote participants having a server class of ASEnterprise. When all remote participants have acknowledged the PrepareXact RPC, any local data changes are written to the database.
Transaction processing for servers in class ASAnywhere is identical to that of server class sql_server (release 10.0 or later).
Transaction processing for servers in class ASIQ is identical to that of server class sql_server (release 10.0 or later).
Component Integration Services sends a prepare transaction command to each server in class sql_server that is version 10.0 or later.
The prepare transaction command is not sent to the following types of servers:
Sybase IQ 11.x
Microsoft SQL Server
Pre-version 10.0 SQL Server
OmniSQL Server 10.1.2
Handling of the prepare transaction command for servers in class direct_connect is identical to that of server class sql_server (version 10.0 or later).
Component Integration Services does not send the prepare transaction command to servers in class db2.
See Also
prepare transaction in the Adaptive Server Reference Manual.
