Hi,
deleting 6500 rows from a partitioned table took 3-4 times longer if the table has no partitions.
ASE 15.5. ESD 5.3 on Solaris 64bit. Sample MonProcessActivity output for unpartitioned Table:
CPUTime WaitTime PhysicalReads LogicalReads PagesRead PhysicalWrites PagesWritten MemUsageKB LocksHeld TableAccesses IndexAccesses TempDbObjects WorkTables ULCBytesWritten ULCFlushes ULCFlushFull ULCMaxUsage ULCCurrentUsage Transactions Commits Rollbacks
----------- ----------- ------------- ------------ ----------- -------------- ------------ ----------- ----------- ------------- ------------- ------------- ----------- --------------- ----------- ------------ ----------- --------------- ------------ ----------- -----------
18100 17400 0 446147 0 6808 6808 162 0 275093 19742 0 7 4464192 6550 0 2024 0 6546 6546 0
Partitioned Table
CPUTime WaitTime PhysicalReads LogicalReads PagesRead PhysicalWrites PagesWritten MemUsageKB LocksHeld TableAccesses IndexAccesses TempDbObjects WorkTables ULCBytesWritten ULCFlushes ULCFlushFull ULCMaxUsage ULCCurrentUsage Transactions Commits Rollbacks
----------- ----------- ------------- ------------ ----------- -------------- ------------ ----------- ----------- ------------- ------------- ------------- ----------- --------------- ----------- ------------ ----------- --------------- ------------ ----------- -----------
87600 23400 0 603242 0 6814 6814 162 0 432195 19742 0 7 4463632 6561 0 2024 0 6546 6546 0
Showplan for the partitioned table:
QUERY PLAN FOR STATEMENT 1 (at line 1).
Optimized using Parallel Mode
STEP 1
The type of query is DELETE.
2 operator(s) under root
|ROOT:EMIT Operator (VA = 2)
|
| |DELETE Operator (VA = 1)
| | The update mode is direct.
| |
| | |SCAN Operator (VA = 0)
| | | FROM TABLE
| | | prognosen3_part
| | | [ Eliminated Partitions : 1 2 3 4 6 ]
| | | Index : prognosen3_aglsec
| | | Forward Scan.
| | | Positioning by key.
| | | Keys are:
| | | aglsec ASC
| | | statnr ASC
| | | modprog ASC
| | | datumsec ASC
| | | dauersec ASC
| | | Using I/O Size 16 Kbytes for index leaf pages.
| | | With LRU Buffer Replacement Strategy for index leaf pages.
| | | Using I/O Size 16 Kbytes for data pages.
| | | With LRU Buffer Replacement Strategy for data pages.
| |
| | TO TABLE
| | prognosen3_part
| | Using I/O Size 16 Kbytes for data pages.
Showplan for the non-partitioned table is equal with exception of the partion elimination line [ Eliminated Partitions : 1 2 3 4 6 ]. I did a similar repro on 15.5 ESD#5.3 on Linux x64 which shows no performance penalty. What is a possible reason for this behavior?
Many thanks
Robert