MODIFY-TRANSACTION-SECURITY

Changes the transaction security parameters

Scope of validity

DBH administration

See also

DBH option TRANSACTION-SECURITY on "TRANSACTION-SECURITY"

Function

The MODIFY-TRANSACTION-SECURITY statement allows you to change the LOCK-TIME parameter, the INACTIVITY-TIME parameter or the LOCK-ESCALATION parameter of the DBH option TRANSACTION-SECURITY during operation.

Only the parameter that is specified in the MODIFY-TRANSACTION-SECURITY statement is changed. All the other values remain unchanged. The values changed for the LOCK-ESCALATION parameter do not take effect until a transaction accesses a table or index after the modification. The changes have no effect on transactions that already have access to a table or index when the option is changed.

MODIFY-TRANSACTION-SECURITY

SELECT = *LOCK-TIME(...) / *INACTIVITY-TIME(...) / *LOCK-ESCALATION(...)
	*LOCK-TIME(...)
		|	TIME = 4 / <integer 1..999>
	*INACTIVITY-TIME(...)
		|	TIME = 40 / <integer 1..999>
	*LOCK-ESCALATION(...)
		|	NUMBER-RECORDS = 4000 / <integer 1..2147483647>
		|	,PERCENTAGE-RECORDS = 50 / <integer 0..100>
		|	,NUMBER-INDEX-VALUES = 1000 / <integer 1..2147483647>

Operands

SELECT = *LOCK-TIME(...)

Changes the time after which an inactive transaction that is locking other transactions is to be rolled back.

TIME = 4 / <integer 1..999>
New value in minutes. The value specified for LOCK-TIME must not be greater than the current value of INACTIVITY-TIME. If it is, the statement is rejected.

SELECT = *INACTIVITY-TIME(...)
Specifies the number of minutes after which an open but inactive transaction is to be rolled back.

TIME = 40 / <integer 1..999>
New value in minutes. The value specified for INACTIVITY-TIME must not be lower than the current value of LOCK-TIME. If it is, the statement is rejected.

SELECT = *LOCK-ESCALATION(...)
Changes the limit values as of which locks escalate. Escalation is when SESAM/SQL attempts to lock the entire index or table.

NUMBER-RECORDS = 4000 / <integer 1..2147483647>
Specifies the number of records in a table that a user can lock. If more records than this are locked, the whole table is locked.

PERCENTAGE-RECORDS = 50 / <integer 0..100>
Specifies the percentage of all the records in the table that a user can lock. If a greater percentage is locked, SESAM/SQL attempts to lock the whole table. If 0 is specified as the percentage, the entire table is locked immediately.

NUMBER-INDEX-VALUES = 1000 / <integer 1..2147483647>
Specifies the number of values that a user can lock in an index. If a larger number than this are locked, an attempt is made to lock the entire index rather than just individual values.

Administration command in ISP format and at the CALL DML interface

Five administration commands with the format OPT,TA-SEC, each with specific operands, correspond to the MODIFY-TRANSACTION-SECURITY administration statement here.

OPT,TA-SEC,L[OCK-TIME]=n
OPT,TA-SEC,I[NACT-TIME]=m
OPT,TA-SEC,E[SCALATE-LOCK],N[UMBER]-R[ECORDS]=l
	{[,P[ERCENTAGE]-R[ECORDS]=k][,N[UMBER]-I[NDEX-VALUES]=j]|
 	[,N[UMBER]-I[NDEX-VALUES]=j][,P[ERCENTAGE]-R[ECORDS]=k]}
OPT,TA-SEC,E[SCALATE-LOCK],P[ERCENTAGE]-R[ECORDS]=k
	{[,N[UMBER]-R[ECORDS]=l][,N[UMBER]-I[NDEX-VALUES]=j]|
 	[,N[UMBER]-I[NDEX-VALUES]=j][,N[UMBER]-R[ECORDS]=l]}
OPT,TA-SEC,E[SCALATE-LOCK],N[UMBER]-I[NDEX-VALUES]=j
	{[,P[ERCENTAGE]-R[ECORDS]=k][,N[UMBER]-R[ECORDS]=l]|
 	[,N[UMBER]-R[ECORDS]=l][,P[ERCENTAGE]-R[ECORDS]=k]}

A number from 1 to 999 can be specified for n and m.

A number from 1 to 2 ³¹-1 can be specified for l and j.

A percentage value from 0 to 100 can be specified for k.