INFORMATION_SCHEMA views in various databases
Few people know about the INFORMATION_SCHEMA views that have been there since SQL-92. Two funny things about that standard: Until the 1990’s, Digital Equipment Corporation was still heavily involved in...
View ArticleUpscene Productions: Database Workbench 4.3.1 free Lite Editions released
Database Workbench is my tool of choice for doing database work: it supports many backends in a consistent manner, and behaves a lot like Delphi (like running and debugging stored procedures)....
View ArticleFirebird and InterBase have single direction indexes for your data safety.
In most database index nodes are doubly linked to allow bi-directional scans. http://is.gd/8CMb7w, however not for InterBase and FireBird, there the reverse link isn’t used because it can be...
View ArticleDatabase Workbench 4.4.1 released (via: News @ Upscene Productions)
I like this Delphi program very much: it is one of the database tools with the widest support of back-ends, and friendliest user interface I know. Oh, and it is by a great Dutch company too: UpScene (:...
View ArticleOn “Bad Habits to Kick : Using AS instead of = for column aliases” (via:...
A while ago, I came across an interesting post Bad Habits to Kick : Using AS instead of = for column aliases by Aaron Bertrand, a major contributor on SQLblog.com – The SQL Server blog spot on the web....
View ArticleDatabase Workbench v4 – version: 4.4.5. got released (via: News @ Upscene...
Today, Version 4.4.5 of Database Workbench got released. It mainly is a bugfix release (15 out of 18 issues were bugfixes, of the rest, 2 are feature requests, 1 enhancement): List of items...
View ArticleVenn Diagrams of SQL Join queries (via: Data Visualization – Google+)
Some great venn diagrams of SQL JOINs via Data Visualization – Google+ of which I wish they were PNG: Thanks to that link, I found the original article and images by C.L. Moffat! Click on the image to...
View ArticleThe curse of “ORA-12560: TNS:protocol adapter error”
Today it is about the curse of ORA-12560: TNS:protocol adapter error Don’t you love the overly generic error messages you often get, especially from Oracle. We log the additional information which...
View ArticleA script to check the frequency of Oracle log switches | Oracle DBA tips
A wile ago, I had a this error when trying to get the TIME portion of a DATE column: ORA-00904: "TIME": invalid identifier This doesn’t work in Oracle, even though when you search for Oracle convert...
View ArticleOracle alter table drop column tips: unused columns
An interesting tip at alter table drop column tips for Oracle: unused columns. I knew about the multi-column syntax for drop column, but the unused columns: You can also drop a table column by marking...
View ArticleReminder to self: app.config and “ORA-12154: TNS:could not resolve the...
When you have one app.config for your whole set of DTAP environments (develop/test/acceptance production), every once in a while you get this error: ORA-12154: TNS:could not resolve the connect...
View ArticleNHibernate, LINQ, Oracle and the placement of Take: avoid “Specified method...
Even though as of 12c R1, Oracle supports a row limiting clause, NHibernate 4.2 with Oracle.DataAccess.dll 2.112.3.0 does not support that. When you let it generate the SQL for a LINQ Take call to...
View ArticleORACLE-BASE – DDL With the WAIT Option (DDL_LOCK_TIMEOUT) in Oracle Database...
To work around this error: ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired ensure your DDL does wait a bit longer than the default of NOWAIT seconds: alter session set...
View Articlesql – Oracle to_date() to parse input to datetime values – via Stack Overflow
The Oracle to_date() function has saved me numerous times parsing date time strings into datetime values like this: to_date('29/07/2015 13:18:00', 'DD/MM/YYYY HH24:MI:SS') One gotcha is that when you...
View ArticleOracle Cross database queries: you need a “database link” for that
I recently learned that you can do cross database queries in Oracle using database links. You need to prefix your objects with the right schema/owner (for instance dbo.) and suffix with an @ sign...
View ArticleCommon Table Expressions: no nesting, but consecutively usage – via Stack...
Common table expressions are awesome. They work in at least Oracle and SQL Server. You cannot nest them, but you can use them consecutively. Thanks spender for explaining that: WITH x AS ( SELECT *...
View ArticleVisual Representation of SQL Joins – CodeProject
I thought I posted a reference to this a long time ago, but didn’t. It’s one of the things I show when explaining joins to people. Sometimes I need it myself too (: The article explains these in...
View ArticleGenerating a million sequential numbers on the fly in a Firebird query – some...
The testing was done with Firebird 2.5.x x86 on Windows 7 x64. Where other relational database platforms have plenty of opportunities to generate sequences (see for instance the below links on Oracle...
View ArticleSQL Fiddle | A tool for easy online testing and sharing of database problems...
Via [WayBack] SQL select only rows with max value on a column, I bumped into http://sqlfiddle.com/#!9/a6c585/1: Application for testing and sharing SQL queries. Source: [WayBack] SQL Fiddle | A tool...
View ArticlePublic database servers
I could not find any vendors/architectures have public database servers. So there is no good way to go beyond SQLFiddle (of which I wrote before in SQL Fiddle | A tool for easy online testing and...
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