m4_comment([$Id: txn_commit.so,v 11.20 2004/12/02 18:21:08 bostic Exp $])

define(M4PAGELOCAL,)
include(tcl/m4.tcl)

m4_tcl_header(txn commit, m4_tcl_txn_commit, [dnl
txn commit
	m4_tcl_arg([-nosync])
	m4_tcl_arg([-sync])
])

m4_p([dnl
The m4_tcl_txn_commit command ends the transaction.])

m4_p([dnl
In the case of nested transactions, if the transaction is a parent
transaction with unresolved (neither committed or aborted) child
transactions, the child transactions are aborted and the commit of the
parent will succeed.])

m4_p([dnl
In the case of nested transactions, if the transaction is a child
transaction, its locks are not released, but are acquired by its parent.
Although the commit of the child transaction will succeed, the actual
resolution of the child transaction is postponed until the parent
transaction is committed or aborted; that is, if its parent transaction
commits, it will be committed, and if its parent transaction aborts, it
will be aborted.])

m4_p([dnl
If the m4_arg(-nosync) option is not specified, a commit log record is
written and flushed to disk, as are all previously written log records.])

m4_p([dnl
The options are as follows:])

m4_tagbegin

m4_tag([-nosync], [dnl
Do not synchronously flush the log. This means the transaction will
exhibit the ACI (atomicity, consistency, and isolation) properties, but
not D (durability); that is, database integrity will be maintained, but
it is possible that this transaction may be undone during recovery
instead of being redone.
m4_p([dnl
This behavior may be set for an entire m4_db environment as part of
the m4_tcl_env_open call.])])

m4_tag([-sync], [dnl
Synchronously flush the log. This means the transaction will exhibit
all of the ACID (atomicity, consistency, isolation and durability)
properties.
m4_p([dnl
This behavior is the default for m4_db environments unless the
m4_arg(-nosync) option was specified to the m4_tcl_env_open or
m4_tcl_txn calls.])])

m4_tagend

m4_p([dnl
After m4_tcl_txn_commit has been called, regardless of its return, the
m4_arg(txn) handle may not be accessed again.  If m4_tcl_txn_commit
encounters an error, this transaction and all child transactions of this
transaction are aborted.])

m4_tcl_ret_standard(m4_tcl_txn_commit)

m4_page_footer