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Aikesheng Open Source Community
Aikesheng Open Source Community
May 7, 2025 · Databases

Differences in Manual Statistics Collection for OceanBase: DBMS_STATS vs ANALYZE Across Versions

This article explains the differences between manual statistics collection methods in OceanBase 3.x and 4.x, compares DBMS_STATS and ANALYZE commands across MySQL and Oracle modes, provides version‑specific tables, detailed code examples for table, partition, and schema level collection, and shows how to verify statistics.

ANALYZEDBMS_STATSOceanBase
0 likes · 9 min read
Differences in Manual Statistics Collection for OceanBase: DBMS_STATS vs ANALYZE Across Versions
21CTO
21CTO
Jun 6, 2022 · Databases

Estimating Oracle Data Pump Export Size Without Impacting Production

This article explains how to use Oracle Data Pump's ESTIMATE and ESTIMATE_ONLY parameters to assess the size of a 1 TB production database for migration, compares BLOCKS and STATISTICS estimation methods, and details best practices for gathering accurate optimizer statistics with ANALYZE and DBMS_STATS.

DBMS_STATSData PumpOracle
0 likes · 10 min read
Estimating Oracle Data Pump Export Size Without Impacting Production
ITPUB
ITPUB
Nov 3, 2016 · Databases

Mastering Oracle Optimizer Statistics: When and How to Collect Them

This guide explains the role of optimizer statistics in Oracle, when to gather them, how to use automatic and manual collection jobs, tune ESTIMATE_PERCENT and METHOD_OPT, manage histograms, handle bind peeking, apply dynamic sampling, and safely test changes with pending statistics.

DBMS_STATSDynamic SamplingESTIMATE_PERCENT
0 likes · 20 min read
Mastering Oracle Optimizer Statistics: When and How to Collect Them
dbaplus Community
dbaplus Community
Oct 24, 2016 · Databases

Why Oracle’s AUTO_SAMPLE_SIZE Misses Skewed Data and How to Fix It

The article explains how Oracle’s default DBMS_STATS.AUTO_SAMPLE_SIZE can produce wildly inaccurate cardinality estimates on highly skewed columns, examines the NewDensity and OldDensity algorithms, demonstrates the problem with real‑world examples, and offers practical solutions such as forcing estimate_percent or disabling NewDensity.

Auto Sample SizeDBMS_STATSDatabase Optimization
0 likes · 10 min read
Why Oracle’s AUTO_SAMPLE_SIZE Misses Skewed Data and How to Fix It
ITPUB
ITPUB
Sep 27, 2016 · Databases

Mastering Oracle Statistics Collection: When, How, and What to Gather

This guide explains how to verify and configure Oracle's automatic optimizer statistics collection, customize collection windows, tailor statistics for large and partitioned tables, detect stale statistics, and decide when to gather histograms, providing practical SQL and PL/SQL examples.

DBMS_STATSHistogramsOracle
0 likes · 10 min read
Mastering Oracle Statistics Collection: When, How, and What to Gather
ITPUB
ITPUB
Sep 13, 2016 · Backend Development

Auto‑Detect Useful Column Groups in Oracle 12c to Improve Query Plans

This guide shows how to use Oracle 12c's DBMS_STATS.SEED_COL_USAGE and REPORT_COL_USAGE to automatically identify useful column groups, create extended statistics, and verify the impact on execution plans with concrete SQL examples.

DBMS_STATSExtended StatsOracle
0 likes · 8 min read
Auto‑Detect Useful Column Groups in Oracle 12c to Improve Query Plans
dbaplus Community
dbaplus Community
Apr 28, 2016 · Databases

Unlock Oracle 12c Optimizer: New Stats, Adaptive Features & Advanced Techniques

This article explores the major enhancements in Oracle 12c's optimizer, including session‑level statistics for global temporary tables, new DBMS_STATS reporting procedures, adaptive features, advanced join elimination methods, incremental and concurrent statistics collection, and automatic column‑group detection, providing practical guidance for DBAs and developers.

12cDBMS_STATSDatabase
0 likes · 23 min read
Unlock Oracle 12c Optimizer: New Stats, Adaptive Features & Advanced Techniques
ITPUB
ITPUB
Nov 27, 2015 · Databases

How to Build an Effective Oracle Statistics Collection Strategy for High‑Volume Systems

This article outlines practical strategies for Oracle DBAs to design, automate, and fine‑tune statistics‑gathering processes in large, high‑concurrency environments, covering automatic options, handling skewed data, partitioned tables, bind variables, and ongoing optimization cycles.

DBMS_STATSDatabase AdministrationPartitioning
0 likes · 10 min read
How to Build an Effective Oracle Statistics Collection Strategy for High‑Volume Systems