How I can enumerate objects in temporary store?

Question

TEMP_IN_USE_SIZE is constantly increased in my application. How i can get information about objects in temporary storage?

Answer 1

Hi Vladimir,
I am not sure wherher you will be able to see actual objects occupying the temporary memoray usage as most of these will belong to internal TT operations when queries use SORTING such as having, group by, order by clauses etc.
However, I guess there is one or two applications that in your case do excessive use of temporary memory space. You can check the temporary memory that a query uses by observing the high water mark for temporary memory usage. The high water mark represents the largest amount of in-use temporary space used since the high water mark was initialized or reset.
For example if you can get hold of query then you can do
1) use dssize command to check TEMP_IN_USE_SIZE and TEMP_IN_USE_HIGH_WATER
Command> dssize
PERM_ALLOCATED_SIZE: 1048576
PERM_IN_USE_SIZE: 284072
PERM_IN_USE_HIGH_WATER: 284072
TEMP_ALLOCATED_SIZE: 524288
TEMP_IN_USE_SIZE: 19447
TEMP_IN_USE_HIGH_WATER: 21543
2) Call the ttMonitorHighWaterReset procedure to reset the TEMP_IN_USE_HIGH_WATER to the current value for TEMP_IN_USE_SIZE.
Command> call ttMonitorHighWaterReset;
Command> dssize
PERM_ALLOCATED_SIZE: 1048576
PERM_IN_USE_SIZE: 284072
PERM_IN_USE_HIGH_WATER: 284072
TEMP_ALLOCATED_SIZE: 524288
TEMP_IN_USE_SIZE: 19447
TEMP_IN_USE_HIGH_WATER: 19447
3) Run your query or the query that is suspected of causing the problem. I guess you need to get the code from developers or through a cronjob running ttXactAdmin <DSN> in regular interval to nidentify what transactions are long running. SAy a code like below with group by, having and order by!
Command> select cust_id "Customer ID",
> count(amount_sold) "Number of orders",
> sum(amount_sold) "Total customer's amount",
> avg(amount_sold) "Average order"
> from sales
> group by cust_id
> having sum(amount_sold) > 94000
> order by 3 desc;
9 rows found.
4) Use dssize to check TEMP_IN_USE_HIGH_WATER for peak memory usage for the query.
Command> dssize
PERM_ALLOCATED_SIZE: 1048576
PERM_IN_USE_SIZE: 284072
PERM_IN_USE_HIGH_WATER: 284072
TEMP_ALLOCATED_SIZE: 524288
TEMP_IN_USE_SIZE: 19447
TEMP_IN_USE_HIGH_WATER: 20199
HTH,
Mich