This is an error that does not happen often. In fact, I came across this for the first time when one of my co-workers Inken HOEIJMANS asked me about this. With her permission, I am reproducing her code solution here. Thank you Inken! She was trying to run a MERGE statement using a large source … Continue reading SQL Server: Fix – Msg 1204, Level 19, State 4 – The instance of the SQL Server Database Engine cannot obtain a LOCK resource at this time…
Simplifying complex problems is difficult but when done, the rewards are definitely worth it. How I single-handedly managed to migrate 55 Billion rows in 4000+ tables: Last year, I created PowerPump a PowerShell based data copy server which continuously migrated 4000+ Oracle tables to SQL Server. It was no simple task given that I had … Continue reading Eating An Elephant – How To Work With Huge Datasets In Oracle And SQL Server
If you are primarily a SQL Server developer and you are moving to Oracle, this is one of the nastiest surprises in store for you. You are so used to rolling back everything including DDL in SQL Server transactions but in Oracle, DDL inside transactions act as COMMIT. Fear not though, there are a ton … Continue reading Oracle Gotcha For The SQL Server Developer – DDL’s COMMIT Transactions Implicitly!
Why DELETE is bad? In Oracle, when it comes to deleting ** A L L ** the data from a table (clearing the contents of a staging table for example), using a DELETE statement is the most inefficient choice. Here are some reasons why DELETE is bad It uses UNDO It uses REDO It fires … Continue reading Oracle – TRUNCATE vs DELETE – Spoiler: TRUNCATE Wins & Why? Hours vs Seconds!
You might have heard the terms UNDO and REDO thrown around in conversations around space usage. In this tip, let us get a basic idea of what UNDO (formerly called ROLLBACK) is in Oracle. I promise you that this will be an interesting read and you will be happy you read this. Unlike SQL Server … Continue reading Oracle UNDO – A Basic Explanation