-
After this rather long discussion of what led the optimizer to choose one index over another — and, more importantly, of the significant consequences this choice brought — let us return to my test query.Bad news though – we are still not done with the optimizer’s internal decision-making, so this means diving yet again into…
-
This post contains 3 parts. Recently I witnessed an interesting case which added a headache to the application owners and the business.Namely, one of the important reports which used to run smoothly all of sudden stopped behaving.Talking numbers, something what people used to get within some seconds (up to 8) unexpectedly took close to 2…
All tags
- 10046 trace (5)
- 10053 trace (7)
- 10200 Trace (1)
- Active Session History (1)
- Auto SQL Plan Management (3)
- AVG_DATA_BLOCKS_PER_KEY (1)
- AVG_LEAF_BLOCKS_PER_KEY (1)
- Batched I/O (1)
- cardinality (4)
- Cartesian Join (2)
- CBO costing (3)
- CDB / PDB (2)
- CLUF (4)
- Clustering Factor (4)
- Converting of CPU costing in 10053 (1)
- CPU_COST in 10053 trace (1)
- Exadata (5)
- FC HBA utilization (1)
- FC host (1)
- Flash (1)
- Flash disk (1)
- Hash Join (2)
- HBA (1)
- I/O throughput (1)
- index leaf block dump (2)
- index tree dump (1)
- Join Permutations (1)
- large SGA (1)
- Linux (1)
- LRU (1)
- Nested Loop (4)
- NSMTIO (4)
- OEM (2)
- Offload (5)
- Oracle 23ai (3)
- Oracle performance (1)
- Oracle tuning (1)
- oradebug (2)
- Parallel Query (2)
- Performance Tuning (1)
- Resc (1)
- Resp (1)
- smart scan (4)
- SQL baseline (3)
- SQL Monitor (4)
- SQL Plan (1)
- SQL Tuning (2)
- system statistics (1)
- Temp tablespace (1)
- Tuning in Multitenant Architecture (2)
- Why Offload does not kick in (2)
Latest posts
- Be cautious when the optimizer estimates a cardinality of 1 – Part2
- Be cautious when the optimizer estimates a cardinality of 1 – Part1
- Be cautious when the optimizer estimates a cardinality of 1 – Part3
- When OEM meets the CBO: cardinality chaos across containers – Part 1
- When OEM meets the CBO: cardinality chaos across containers – Part 2
- Auto SQL Plan Management (look under the hood) – part 1
- Auto SQL Plan Management (look under the hood) – part 3
- Auto SQL Plan Management (look under the hood) – part 2
- Converting of CPU Costing in the Cost Based Optimizer 10053 Trace File
- Why this extra physical read while performing index scan?