Add Space to shared pool The library cache miss ratio tells the DBA whether or not to add space to the shared pool, and it represents the…
View More Viewing the Library Cache Statistics
Category: Oracle
Oracle
Oracle/ SQL Wait Events
1. What are wait events? Wait events are characteristic parts of theย Oracleย kernel source code that can contain Oracle sessions during execution. Oracle provides statistical information…
View More Oracle/ SQL Wait Events
Streams Pool
Sometimes conventional wisdom isnโt so conventional, or common. As a case-in-point DBAs may believe that the STREAMS pool is reserved strictly for streams processes. That…
View More Streams Pool
What is SQL PROFILE in oracle?
You might have heard of SQL profile and SQL baselines in performance tuning chapters. Lets today go through details about sql profile. What is SQL…
View More What is SQL PROFILE in oracle?
Partition Pruning and NLS Settings
NLS (National Language Support) parameters are very useful for multilingual applications in an Oracle database. But it is important to understand their impact on query…
View More Partition Pruning and NLS Settings
How to Lock, Unlock, Transfer Statistics in oracle
Locking Stats To prevent statistics being overwritten, you can lock the stats at schema, table or partition level. EXEC DBMS_STATS.lock_schema_stats(‘SCOTT’); EXEC DBMS_STATS.lock_table_stats(‘SCOTT’, ‘EMP’); EXEC DBMS_STATS.lock_partition_stats(‘SCOTT’,…
View More How to Lock, Unlock, Transfer Statistics in oracle
Finding Empty Tablespaces in Oracle
I’m given a task to find the empty tablespaces.I’ve checked dev server and majority of the tables’ stats were locked.This solution takes time but works.…
View More Finding Empty Tablespaces in Oracle
Selectivity vs Cardinality
What is selectivity? Selectivity is the estimated proportion of the rows that will return from our query based on the total rows of that table.…
View More Selectivity vs Cardinality
Enable or Disable Table Locks in Oracle Database
Table Locks are an important part of Oracle Working Mechanism as they provide security from unwanted deletion or modification of table’s data which can sometimes…
View More Enable or Disable Table Locks in Oracle Database
Column Histograms in Oracle 11g
Data skew in a column can make it difficult for the optimizer to accurately estimate the cardinality of an operation. Without a histogram it will…
View More Column Histograms in Oracle 11g