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Announcing SLOB 2.5.3

This is just a quick blog post to inform readers that SLOB 2.5.3 is now available at the following webpage: click here.

SLOB 2.5.3 is a bug fix release. One of the fixed bugs has to do with how SLOB sessions get connected to RAC instances. SLOB users can surely connect to the SCAN service but for more repeatable testing I advise SLOB 2.5.3 and SQL*Net services configured one per RAC node. This manner of connectivity establishes affinity between schemas and RAC nodes. For example, repeatability is improved if sessions performing SLOB Operations against, say, user7’s schema, it is beneficial to do so connected to the same RAC node as you iterate through your testing.

The following is cut and pasted from SLOB/misc/sql_net/README:

Oracle 19c Automatic Indexing: Non-Equality Predicates Part II (Let’s Spend The Night Together)

In my previous post in this series, I discussed out Automatic Indexing currently does not consider Non-Equality predicates. Automatic Indexing will index columns based only on Equality predicates. So how does Oracle handle the scenario when an SQL has a mixture of both Equality and Non-Equality predicates? I’ll begin by creating two very similar tables, […]

Hint Errors

This is a list of possible explanations of errors that you might see in the Hint Report section of an execution plan. It’s just a list of the strings extracted from a chunk of the 19.3 executable around the area where I found something I knew could be reported, so it may have some errors and omissions – but there are plenty of things there that might give you some idea why (in earlier versions of Oracle) you might have seen Oracle “ignoring” a hint:

CBO Example

A little case study based on an example just in on the Oracle-L list server. This was supplied with a complete, working, test case that was small enough to understand and explain very quickly.

The user created a table, and used calls to dbms_stats to fake some statistics into place. Here, with a little cosmetic editing, is the code they supplied.

APEX Application Development Service on Oracle Cloud

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A few days ago Oracle announced the APEX Application Development Service on Oracle Cloud.

Announcement: Both Of My Oracle Webinars Scheduled For February 2021 !!

I’m please to announce that both of my highly acclaimed webinars scheduled for February are now confirmed. These webinars are a must for any Oracle DBA or Developer interested in designing, developing or maintaining high performance, highly scalable Oracle-based applications or databases. However only a few places are currently available on each webinar with numbers […]

Supplemental Defect

Here’s an anomaly that appeared in a question on the ODC recently about tweaking the output of dbms_metadata.get_ddl(), As the title suggests, though, this posting isn’t about the dbms_metadata package it’s about supplemental logging and something that should not to be possible and may have unfortunate side effects.

We start with a little script that creates a table, inserts some data, adds a couple of constraints, and then introduces some supplemental logging requirements. As the script header indicates I’ve only tested this on 19.3.0.0:

Video : JSON Data Type in Oracle Database 21c

In today’s video we demonstrate the JSON data type, introduced in Oracle database 21c.

The video is based on this article.

It assumes knowledge of existing JSON support in the Oracle database. If you are not familiar with the functionality Oracle have been including in the database since Oracle 12c, you might want to check out these.

Oracle Database 21c : It’s New to Everyone

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A few days ago Oracle made the official announcement about the release of Oracle database 21c (here). This was a rather late announcement, as the product has been available on Oracle Cloud for over a month, but that’s not the subject of this post.

With each new release I feel the need to write a post like this, so here goes…

Between

Reading Richard Foote’s latest blog note about automatic indexing and “non-equality” predicates I was struck by a whimsical thought about how the optimizer handles “between” predicates. (And at the same time I had to worry about the whimsical way that WordPress treats “greater than” and “less than” symbols.)

It’s probably common knowledge that if your SQL has lines like this:

columnA between {constant1} and {constant2}

the optimizer will transform them into lines like these: