Oracle DBA

XTTS (Cross-Platform Transportable Tablespaces) is used to migrate large Oracle databases between different platforms while minimizing downtime.It combines three technologies: The idea is: Below is the full operational procedure used in real migrations. Step 1 — Verify Platform Compatibility Identify the source and target platform endian format. SELECT platform_name, endian_formatFROM v$transportable_platformORDER BY platform_name; Confirm the […]

Below are the most effective techniques used by Oracle DBAs to speed up RMAN backups. 1. Increase RMAN Channels (Parallelism) RMAN uses channels as streams for reading data files and writing backup pieces. Increasing the number of channels enables parallel backup operations, significantly improving throughput. Example: CONFIGURE DEVICE TYPE DISK PARALLELISM 4; Or manually allocate […]

1. Clarify the Problem Scope First establish what exactly is slow. Key questions: Useful checks: Example query: SELECT sql_id, sql_textFROM v$sqlWHERE parsing_schema_name = ‘SCHEMA_NAME’ORDER BY elapsed_time DESC; This helps identify top SQL consuming resources. 2. Check Current Database Activity Verify if the issue is currently happening. Key views: Example: SELECT sid, serial#, username, sql_id, event, […]

1. DB Time Much Higher Than DB CPU Pattern Meaning Sessions are mostly waiting, not using CPU. Likely Causes Example Metric Value DB Time 8000 sec DB CPU 1200 sec This clearly indicates wait-based performance issues. 2. High db file sequential read Pattern Top Timed Event shows: db file sequential read Meaning Excessive single-block reads, […]