Historical Oracle ANSI Join Limit: 1,050 Columns
This note refers to an old Oracle 10g issue in which very wide ANSI join queries could fail after internal query transformation. The reported threshold was roughly 1,050…
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Featured series · 3 parts
Oracle SQL tuning with AWR & ASH
Follow the investigation from the first slowdown to a stable execution plan.
01 · AWR
Find and prove the regression
Identify the SQL, compare execution plans, and establish what changed.
02 · ASH
Find where the time went
Use ASH and runtime plans to understand waits and execution work.
03 · Plan stability
Tune and stabilize the plan
Evaluate advisor recommendations and stabilize a proven execution plan.
Latest articles
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Oracle: CPU Used by Each Database Session
Oracle exposes cumulative database CPU time for each session through V$SESSTAT. Join it to V$STATNAME by name—never hard-code a statistic number, because statistic numbers can change between releases.…
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Oracle IPC Resources: Map Shared Memory to an Instance
On UNIX and Linux hosts with several Oracle instances, ipcs can show many shared-memory and semaphore resources without identifying the owning database clearly. Oracle’s sysresv utility maps System…
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RMAN-10035 / ORA-19502 / ORA-27030 Media Manager Errors
When RMAN reports RMAN-10035, ORA-19502, and ORA-27030 during an SBT backup, the useful diagnosis is usually in the final media-manager message. The Oracle stack says the backup write…
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Trigger RMAN Archivelog Backups Based on Filesystem Usage
A rapidly growing archive destination can fill during bulk loads or data migrations. A usage-triggered RMAN job is a useful emergency backstop, but it should complement—not replace—scheduled archivelog…
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SQL Server: Safely Attach Multiple Databases
The old sp_attach_db procedure is deprecated. Modern SQL Server uses CREATE DATABASE … FOR ATTACH, and every data and log file must be accounted for. Prefer backup and…
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Oracle DBNEWID (NID): Change a DBID or Database Name
Oracle’s DBNEWID utility, invoked as nid, can change a database identifier (DBID), a database name (DBNAME), or both. This is useful after cloning a database that must be…
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Changing an Oracle DBID: Oracle 8i and 9i Considerations
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Script SQL Server Agent Jobs with PowerShell and SMO
SQL-DMO and ActiveX Script job steps belong to an older SQL Server era. For current systems, use SQL Server Management Objects (SMO) from PowerShell and the maintained SqlServer…
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Monitor Oracle Processes and Threads on Windows
On Windows, Oracle database activity is easiest to diagnose by correlating Oracle sessions with operating-system process and thread identifiers. The old Quick Slice utility is no longer needed;…