If you’re a DBA, it’s likely that you’ve encountered systems where a lot of SQL statements have been hinted almost as a matter of policy. Perhaps you’d like to...
If you’re a DBA, it’s likely that you’ve encountered systems where a lot of SQL statements have been hinted almost as a matter of policy. Perhaps you’d like to figure out if these hints are actually helping. You might like to demonstrate to a development team that they should probably dial down their enthusiasm for micro-managing the Oracle Optimizer. Sometimes, you might want to apply a hints on-the-fly. A while ago, Maria Colgan wrote a couple of posts (here and here) on...
If you’re a DBA, it’s likely that you’ve encountered systems where a lot of SQL statements have been hinted almost as a matter of policy. Perhaps you’d like to figure out if these hints are actually...
html{font-size:45%;} tbody{font-family:Arial, Helvetica, sans-serif; font-size:110%;} .mycode{font-family: monospace; font-size:100%;} .ilc{font-family:...
html{font-size:45%;} tbody{font-family:Arial, Helvetica, sans-serif; font-size:110%;} .mycode{font-family: monospace; font-size:100%;} .ilc{font-family: monospace; font-size:100%;} .u14mnav{font-size:100%;} .u14logo{font-size:100%;} var h1Headers = document.getElementsByTagName("h1"); for (var i = 0; i< h1Headers.length; i++) { h1Headers[i].style.fontSize = '28px'; } Our last post on SQL patches generated a lot of comments and questions. Today I will address a couple of...
html{font-size:45%;} tbody{font-family:Arial, Helvetica, sans-serif; font-size:110%;} .mycode{font-family: monospace; font-size:100%;} .ilc{font-family: monospace;...
html{font-size:45%;} tbody{font-family:Arial, Helvetica, sans-serif; font-size:110%;} .mycode{font-family: monospace; font-size:100%;} .ilc{font-family: monospace; font-size:100%;} .u14mnav{font-size:100%;} .u14logo{font-size:100%;} var h1Headers = document.getElementsByTagName("h1"); for (var i = 0; i< h1Headers.length; i++) { h1Headers[i].style.fontSize = '28px'; } From Oracle Database 12c Release 2 onwards there's a public API call to create SQL patches using...
In our previous blog post I described how you can use the new diagnostic event infrastructure in Oracle Database 11g to capture an Optimizer trace (10053) for...
In our previous blog post I described how you can use the new diagnostic event infrastructure in Oracle Database 11g to capture an Optimizer trace (10053) for any SQL statement once you have its SQL_ID. The approach I showed using the traditional ‘Alter session set event’ approach and thus required you to execute the SQL statement. What I forgot to mention (and have been scolded for) was that you can also use the new infrastructure to generate an Optimizer trace for any SQL...
In our previous blog post I described how you can use the new diagnostic event infrastructure in Oracle Database 11g to capture an Optimizer trace (10053) for any SQL statement once you have...
In most cases the first step in debugging a performance problem caused by a plan change is to visually inspect both of the execution plans generated by the...
In most cases the first step in debugging a performance problem caused by a plan change is to visually inspect both of the execution plans generated by the query optimizer. Usually the customer has a known plan that performed well and the new plan that performs worse. Visual inspection of plans is easy when the query is not too complex but becomes a tedious exercise when the query is complex (involving tens of joins, sub-queries, views, etc).This article introduces a new plan...
In most cases the first step in debugging a performance problem caused by a plan change is to visually inspect both of the execution plans generated by the query optimizer. Usually the customer has a...
The answer to this question is yes. The Oracle Database provides a diagnostic tool called SQL Test Case Builder. In this article, we explain what SQL Test Case...
The answer to this question is yes. The Oracle Database provides a diagnostic tool called SQL Test Case Builder. In this article, we explain what SQL Test Case Builder is, and how to use it with examples. Why SQL Test Case Builder? For most SQL problems, the single most important factor for a speedy bug resolution is to obtain a reproducible test case. However, this is normally the longest and most painful step for customers. The goal of the SQL Test Case Builder (TCB) is to...
The answer to this question is yes. The Oracle Database provides a diagnostic tool called SQL Test Case Builder. In this article, we explain what SQL Test Case Builder is, and how to use it...
