WebMay 27, 2024 · InnoDB handles SELECT COUNT (*) and SELECT COUNT (1) operations in the same way. There is no performance difference. For MyISAM tables, COUNT (*) is optimized to return very quickly if the SELECT retrieves from one table, no other columns are retrieved, and there is no WHERE clause. This optimization only applies to MyISAM tables, … WebAug 30, 2024 · This query: select count(*) from planner_event takes a very long time to run - so long, I gave up and killed it before it finished. However, when I run explain select …
How to count SQL databases quickly in PostgreSQL and MySQL
WebFeb 7, 2024 · Accompanied by the slow_query_log variable are the long_query_time and min_examined_row_limit which impacts how the slow query logging works. Basically, the slow query logs work as SQL statements that take more than long_query_time seconds to execute and also require at least min_examined_row_limit rows to be examined. WebDescription: when i connect mysql server for windows on my laptop, the select count(*) is very slow, so i created 100 thousands rows data, it's runed 13s.i tried most times, always this. the server version is 8.0.22. but the same data, on server for linux, less than 1s. version is 8.0.22 too. then i connect mysql server for windows on my desktop, server version is … greenwhich chrome and brass towel ring
MySQL Bugs: #97709: MySQL 8 Select Count(*) is very slow
WebOct 12, 2016 · A note about count(1) vs count(*).One might think that count(1) would be faster because count(*) appears to consult the data for a whole row. However the opposite is true. The star symbol is meaningless here, unlike its use in SELECT *.PostgreSQL parses The expression count(*) as a special case taking no arguments. (Historically the … WebMar 24, 2024 · The first problem after migration is: a count(*) over 100'000 records takes 15 seconds. Inf 5.7 it tooks about 0.1 second. after testing an comparing i found out that it has nothing to do with the record number (same result with just 2 records),but adding an extra index to the primary key field (id) helped. fnz group edinburgh