How to identify SQL performing poorly on an APEX application?

Oracle Application Express (APEX) is a great tool to rapidly develop applications on top of an Oracle database. While developing an internal application we noticed that some pages were slow, meaning taking a few seconds to refresh. Suspecting there was some poorly performing SQL behind those pages, we tried to generate a SQL Trace so we could review the generated SQL. Well, there is no out-of-the-box instrumentation to turn SQL Trace ON from an (more...)

Free script to generate a Line Chart on HTML

Performance Metrics are easier to digest if visualized trough some Line Charts. OEM, eDB360, eAdam and other tools use them. If you already have a SQL Statement that provides the Performance Metrics you care about, and just need to generate a Line Chart for them, you can easily create a CSV file and open it with MS-Excel. But if you want to build an HTML Report out of your SQL, that is a bit (more...)

eAdam

Enkitec’s Oracle AWR Data Mining Tool

eAdamEAdam is a free tool that extracts from an Oracle database a subset of data and metadata with the objective to perform some data mining using a separate staging Oracle database. The data extracted is relevant to Performance Evaluations (PE) and/or to Sizing and Provisioning (SP) projects. Most of the data eAdam extracts is licensed by Oracle under the Diagnostics Pack, and some under the Tuning Pack. Therefore, in (more...)

eDB360

Enkitec’s Oracle Database 360-degree View

eDB360

EDB360 is a free tool that executes on an Oracle database and produces a compressed file which includes a large set of small Reports. This set of Reports provides a 360-degree view of an Oracle Database. EDB360 is mostly used for one of the following 3 reasons, listed here in order of frequency of use: 1) Keystone of an Oracle database Health-Check. 2) Kick-off for an Oracle database Performance Evaluation. 3) High-level (more...)

Free script to very quickly and cheaply estimate the size of an index if it were to be rebuilt

A good friend of mine recently asked me if edb360 included a section showing indexes that would benefit of a rebuild. I replied “not yet” and basically committed to add something. This topic of the needs versus the implications of rebuilding an index has been recently discussed in Richard Foote’s Blog. In my opinion, if you want to know more about indexes, Richard’s blog is one of the first stops. To my surprise and delight, (more...)

SQLTXPLAIN PL/SQL Public APIs to execute XTRACT from 3rd party tools

Many tools offer Public APIs, which expose some functionality to other tools. SQLTXPLAIN contains also some Public APIs. They are provided by package SQLTXADMIN.SQLT$E. I would say the most relevant one is XTRACT_SQL_PUT_FILES_IN_DIR. This blog post is about this Public API and how it can be used by other tools to execute a SQLT XTRACT from PL/SQL instead of SQL*Plus.

Imagine a tool that deals with SQL statements, and with the click of a button it invokes (more...)

About Oracle ACE and Kscope14 at ODTUG

Oracle ACE Dinner at Kscope14

Last night we had our get together for Oracle ACE members at Kscope14. Of course food and drinks were great, but a lot more important was the crowd. I am surprised to see how fast this ACE program is growing, and I believe the impact to our Oracle community is gaining momentum with it.

I will miss Kscope14 and I will submit some topics to Kscope15 soon. I already have a few new topics in mind, tailored to (more...)

Creating a SQL Plan Baseline out of a modified SQL

While delivering a session at KSCOPE 14, I was asked a very good question: Can I create a SQL Plan Baseline for an Original SQL out of a Modified SQL? In other words, query Q1, which performs poorly, has SQL_ID1 and SQL_HANDLE1 with a poorly performing Execution Plan with Hash Value PHV1. With a small modification to this query, like adding a CBO Hint or removing one, we obtain query Q2, which performs well, (more...)

Skipping ACS ramp-up using a SQL Patch

As I prepare for one of my sessions at ODTUG Kscope14 I came across the typical situation of having a SQL for which I wanted to produce multiple optimal execution Plans on an 11g environment. As you may know, with Adaptive Cursor Sharing (ACS) this is possible and automatic, but the problem is that sometimes the ACS ramp-up process causes some suboptimal Execution Plans. If you want to skip this ACS ramp-up process, lets say for a SQL (more...)

How to upgrade Dynamic Sampling on a Query already using an imported SQL Profile

Problem

I have this query that references a couple of Global Temporary Tables (GTT). These GTT have no CBO Statistics, thus Dynamic Sampling (DS) is used on them. The problem is default value of 2 at the instance level samples only 64 blocks and these GTT are large. Testing with DS on larger samples provides better quality on these dynamic statistics and a better performing Execution Plan for this particular SQL.

This SQL already uses an (more...)