lct_admin

Manages the last-chance threshold (LCT). It returns the current value of the LCT and aborts transactions in a transaction log that has reached its LCT.

Syntax

lct_admin({{"lastchance" | "logfull" | "reserved_for_rollbacks"},
	database_id
	|"reserve", {log_pages | 0 }
	| "abort", process-id [, database-id]})

Parameters

lastchance – creates a LCT in the specified database.
logfull – returns 1 if the LCT has been crossed in the specified database and 0 if it has not.
reserved_for_rollbacks – determines the number of pages a database currently reserved for rollbacks.
database_id – specifies the database.
reserve – obtains either the current value of the LCT or the number of log pages required for dumping a transaction log of a specified size.
log_pages – is the number of pages for which to determine a LCT.
0 – returns the current value of the LCT. The size of the LCT in a database with separate log and data segments does not vary dynamically. It has a fixed value, based on the size of the transaction log. The LCT varies dynamically in a database with mixed log and data segments.
abort – aborts transactions in a database where the transaction log has reached its last-chance threshold. Only transactions in log-suspend mode can be aborted.
logsegment_freepages – describes the free space available for the log segment. This is the total value of free space, not per-disk.
process-id – is the ID (spid) of a process in log-suspend mode. A process is placed in log-suspend mode when it has open transactions in a transaction log that has reached its last-chance threshold (LCT).
database-id – is the ID of a database with a transaction log that has reached its LCT. If process-id is 0, all open transactions in the specified database are terminated.

Examples

Example 1 – Creates the log segment last-chance threshold for the database with dbid 1. It returns the number of pages at which the new threshold resides. If there was a previous last-chance threshold, it is replaced:
```
select lct_admin("lastchance", 1)
```
Example 2 – Returns 1 if the last-chance threshold for the database with dbid of 6 has been crossed, and 0 if it has not:
```
select lct_admin("logfull", 6)
```
Example 3 – Calculates and returns the number of log pages that would be required to successfully dump the transaction log in a log containing 64 pages:
```
select lct_admin("reserve", 64)
```
```
-----------
         16 
```
Example 4 – Returns the current last-chance threshold of the transaction log in the database from which the command was issued:
```
select lct_admin("reserve", 0)
```
Example 5 – Aborts transactions belonging to process 83. The process must be in log-suspend mode. Only transactions in a transaction log that has reached its LCT are terminated:
```
select lct_admin("abort", 83)
```
Example 6 – Aborts all open transactions in the database with dbid of 5. This form awakens any processes that may be suspended at the log segment last-chance threshold:
```
select lct_admin("abort", 0, 5)
```
Example 7 – Determines the number of pages reserved for rollbacks in the pubs2 database, which has a dbid of 5:
```
select lct_admin("reserved_for_rollbacks", 5, 0)
```
Example 8 – Describes the free space available for a database with a dbid of 4:
```
select lct_admin("logsegment_freepages", 4)
```

Usage

lct_admin, a system function, manages the log segment’s last-chance threshold. For general information about system functions, see Transact-SQL Users Guide.
If lct_admin(“lastchance”, dbid) returns zero, the log is not on a separate segment in this database, so no last-chance threshold exists.
Whenever you create a database with a separate log segment, the server creates a default last chance threshold that defaults to calling sp_thresholdaction. This happens even if a procedure called sp_thresholdaction does not exist on the server at all.

If your log crosses the last-chance threshold, the SAP ASE server suspends activity, tries to call sp_thresholdaction, finds it does not exist, generates an error, then leaves processes suspended until the log can be truncated.
To terminate:
- The oldest open transaction in a transaction log that has reached its LCT, enter the ID of the process that initiated the transaction.
- All open transactions in a transaction log that has reached its LCT, enter 0 as the process-id, and specify a database ID in the database-id parameter.

Standards

ANSI SQL – Compliance level: Transact-SQL extension.

Permissions

The permission checks for lct_admin differ based on your granular permissions settings.

Granular Permissions	Description
Enabled	With granular permissions enabled, you must have `manage database` permission to execute lct_admin abort. Any user can execute the other lct_admin options.
Disabled	With granular permissions disabled, you must be a user with sa_role to execute lct_admin abort. Any user can execute the other lct_admin options.