Tuning a SELECT query can involve several steps and tools, including the SQL Tuning Advisor and the EXPLAIN PLAN. I personally use SQL Tuning Advisory as my first preference, but selecting tools is decided as per the problem summary. Identify the Performance Issue: Determine if the query is running slowly or causing performance bottlenecks. Review the Query: Ensure the query is written efficiently. Check for unnecessary complexity, redundant conditions, and suboptimal joins. Use EXPLAIN PLAN: Generate an execution plan using the EXPLAIN PLAN statement to understand how Oracle executes the query. Look for full table scans, nested loops, and other potentially inefficient operations. Syntax: EXPLAIN PLAN FOR your_select_query; Analyze the Execution Plan: Identify which parts of the query are consuming the most resources. Check for missing indexes or suboptimal join methods. Optimize Query Structure: Simplify complex queries. Rewrite subqueries as joins or vice versa if it improves performance. Use appropriate indexing. Add/Modify Indexes: Ensure that the columns used in WHERE clauses, joins, and ORDER BY clauses are indexed appropriately. Consider adding composite indexes if multiple columns are frequently queried together. Statistics Collection: Ensure that table and index statistics are up to date using DBMS_STATS.GATHER_TABLE_STATS and DBMS_STATS.GATHER_INDEX_STATS. Use SQL Tuning Advisor: Run the SQL Tuning Advisor to get automated suggestions for query optimization. It provides recommendations on indexes, SQL profiles, and query restructuring. Syntax: EXEC DBMS_SQLTUNE.create_tuning_task(sql_text => 'your_select_query'); Review Advisor Recommendations: Assess the recommendations provided by the SQL Tuning Advisor and implement the ones that make sense for your context. Hope it helped :)
Slow uploading of files to an Oracle server can be caused by various factors. To diagnose and resolve this issue, consider the following steps: Network Bandwidth and Latency: Check Network Speed: Ensure that the network connection between the client and the Oracle server is fast and reliable. Latency: High latency can slow down file uploads. Use tools like ping or traceroute to diagnose network delays. Server Resources: CPU and Memory: Ensure that the server has adequate CPU and memory resources. High CPU or memory usage can slow down file uploads. Disk I/O: Slow disk performance can affect file uploads. Check disk I/O performance using tools like iostat or vmstat. Oracle Database Configuration: Direct Path Load: For large file uploads, consider using direct path load methods such as SQL*Loader with the DIRECT parameter, which bypasses some of the overhead of conventional path loads. BLOB/CLOB Data Types: If you are uploading large files as BLOB or CLOB, ensure that you are using efficient methods to write these large objects. Database Parameters: LOG_BUFFER: A small log buffer can slow down file writes. Increase the size of the LOG_BUFFER parameter if necessary. DB_FILE_MULTIBLOCK_READ_COUNT: Adjust this parameter to optimize the number of blocks read in one I/O operation. Hope it helped !! :)
your videos are good enough, keep up the good work
Glad you like them! Thanks :)
Nice one sir expecting more videos
Thanks for your comment, every saturday one video will be uploaded.
Thank you sir . So beautifully explained..
Thank you :)
Nice one
Hi there, good one. How would you tune a select query. Do you use sql tuning advisor or explain plan.
Tuning a SELECT query can involve several steps and tools, including the SQL Tuning Advisor and the EXPLAIN PLAN.
I personally use SQL Tuning Advisory as my first preference, but selecting tools is decided as per the problem summary.
Identify the Performance Issue:
Determine if the query is running slowly or causing performance bottlenecks.
Review the Query:
Ensure the query is written efficiently. Check for unnecessary complexity, redundant conditions, and suboptimal joins.
Use EXPLAIN PLAN:
Generate an execution plan using the EXPLAIN PLAN statement to understand how Oracle executes the query.
Look for full table scans, nested loops, and other potentially inefficient operations.
Syntax: EXPLAIN PLAN FOR your_select_query;
Analyze the Execution Plan:
Identify which parts of the query are consuming the most resources.
Check for missing indexes or suboptimal join methods.
Optimize Query Structure:
Simplify complex queries.
Rewrite subqueries as joins or vice versa if it improves performance.
Use appropriate indexing.
Add/Modify Indexes:
Ensure that the columns used in WHERE clauses, joins, and ORDER BY clauses are indexed appropriately.
Consider adding composite indexes if multiple columns are frequently queried together.
Statistics Collection:
Ensure that table and index statistics are up to date using DBMS_STATS.GATHER_TABLE_STATS and DBMS_STATS.GATHER_INDEX_STATS.
Use SQL Tuning Advisor:
Run the SQL Tuning Advisor to get automated suggestions for query optimization.
It provides recommendations on indexes, SQL profiles, and query restructuring.
Syntax: EXEC DBMS_SQLTUNE.create_tuning_task(sql_text => 'your_select_query');
Review Advisor Recommendations:
Assess the recommendations provided by the SQL Tuning Advisor and implement the ones that make sense for your context.
Hope it helped :)
@@anishkumarvideos Thank you
Just wow
What about slow uploading of files.
Slow uploading of files to an Oracle server can be caused by various factors.
To diagnose and resolve this issue, consider the following steps:
Network Bandwidth and Latency:
Check Network Speed: Ensure that the network connection between the client and the Oracle server is fast and reliable.
Latency: High latency can slow down file uploads. Use tools like ping or traceroute to diagnose network delays.
Server Resources:
CPU and Memory: Ensure that the server has adequate CPU and memory resources. High CPU or memory usage can slow down file uploads.
Disk I/O: Slow disk performance can affect file uploads. Check disk I/O performance using tools like iostat or vmstat.
Oracle Database Configuration:
Direct Path Load: For large file uploads, consider using direct path load methods such as SQL*Loader with the DIRECT parameter, which bypasses some of the overhead of conventional path loads.
BLOB/CLOB Data Types: If you are uploading large files as BLOB or CLOB, ensure that you are using efficient methods to write these large objects.
Database Parameters:
LOG_BUFFER: A small log buffer can slow down file writes. Increase the size of the LOG_BUFFER parameter if necessary.
DB_FILE_MULTIBLOCK_READ_COUNT: Adjust this parameter to optimize the number of blocks read in one I/O operation.
Hope it helped !! :)
Is there any class your side conducting for performance tuning ?
Yes , we are going to publish full course on PT very soon !!!