Question : I am trying to partition a table with 200 million records in it. This table already exists: CREATE […]
Tag: locking
When changing the size of a nvarchar column, do I need to drop the unique index? And will the table get locked when recreating the index?
Question : In our database a big table exists that more or less looks like this: CREATE TABLE dbo.production_data ( […]
What is the performance cost of enabling “log_lock_waits” on Postgres?
Question : I am trying to understand what is the performance cost of enabling log_lock_waits on Postgres. As per this […]
How mysql (innodb) handles auto increment column
Question : I am working on a OLTP environment with multiple parallel write operation. I found this in documentation about […]
LOAD DATA (400k rows) INFILE takes about 7 minutes, cannot kill the “logging slow query” process?
Question : MySQL version: 5.5.13 The query that I’m using: SET AUTOCOMMIT=0; LOAD DATA INFILE ‘/data10/select_into.outfile/v3_zone_date.out’ INTO TABLE v3_zone_date FIELDS […]
Can I set the maximum locking level that a transaction can acquire?
Question : What I want to achieve is something like this: SET LOCAL max_locking_level=”ACCESS SHARE”; ALTER TABLE foo ALTER COLUMN […]
Locking issue with concurrent DELETE / INSERT in PostgreSQL
Question : This is pretty simple, but I’m baffled by what PG does (v9.0). We start with a simple table: […]
What does innodb_table_locks setting do exactly?
Question : Can someone please explain how this setting affects the locking behaviour in innodb (with an example). I ran […]
How do I place an UpdateLock on a row with an index
Question : Let’s assume I have a table like this on a SQL Server 2014: CREATE TABLE Accounts ( Id […]
Is this update, select combination query thread safe?
Question : I have a table called seats, which has a schema like this id,taken For each user, I take […]