Connection1: BEGIN; SELECT * FROM world.city WHERE ID = 130 FOR SHARE; Connection2: SELECT engine, thread_id, object_schema, object_name, lock_type, lock_mode, lock_status, lock_data FROM performance_schema.data_locks; +--------+-----------+---------------+-------------+-----------+---------------+-------------+-----------+ | engine | thread_id | object_schema | object_name | lock_type | lock_mode | lock_status |…
Brief I'm getting inserts into a transactions log table out of desired (logical) order - where a deposit to a an accountinstance+iteration occurs before that iteration exists, logically. Technology We're using PostgreSQL (13.x). Background I'm writing code that must be…
I am trying to build a movie ticket booking application just to practice for interview low level design perspective. A theater can have multiple screens and each screen as some seats capacity. A show is a movie which will be…
I was comparing the performance of a approximate counter and a simple concurrent counter from the book operating system three easy pieces Simple concurrent counter is a structure with a lock and the mutex, typedef struct __counter_t { int value;…
My Google App Engine application (Python3, standard environment) serves requests from users: if there is no wanted record in the database, then create it. Here is the problem about database overwriting: When one user (via browser) sends a request to…
I'm trying to understand if the node-cache package uses locks for the cache object and can't find anything. I tried to look at the source code and it doesn't look like it, but this answer suggests otherwise with the quote:…
We run a CentOS DirectAdmin install with MariaDB 10.2.14 where on Magento is installed. Currently our DB locks very often when a process runs, so all other processes are waiting until the current process finishes. This is quite a problem,…
When I edit ImageView, UIButton, or other objects on the StoryBoard Canvas, it is very hard to select the layer behind them. I want to lock selection for top layer like Photoshop, or in 3DMax what is known as Freeze…