will show table status display exact rows in the table?

Question

I have a table in DB and it is approx 90 GB in space. I tried to count no of rows in the table select count(idNewsNotification) from notification and it resulted

4982397

1 row in set (59 min 48.35 sec)

But when I queried using show table status like <table_name> it is showing that

 Engine: InnoDB
 Version: 10
 Row_format: Compact
 Rows: 8631267
 Avg_row_length: 11237
 Data_length: 96996425728
 Max_data_length: 0
 Index_length: 175374336
 Data_free: 0
 Auto_increment: NULL
 .....

What is the perfect procedure for knowing the no of records in the table ?

Answer 1

The fact that your count took an hour implies that you're running InnoDB (which doesn't cache this data).

As such, the table status is an approximation based on other factors, and is not to be trusted.

The count(*) would be accurate, but a pain to wait for.

From the doc:

Some storage engines, such as MyISAM, store the exact count. For other storage engines, such as InnoDB, this value is an approximation, and may vary from the actual value by as much as 40 to 50%. In such cases, use SELECT COUNT(*) to obtain an accurate count.

Answer 2

This is not a good one, in some cases.

For InnoDB tables, the row count is only a rough estimate used in SQL optimization. (This is also true if the InnoDB table is partitioned.)

TEST:

I have the same db (dumped and imported on different server) both innoDB

Same table:

Server One: 49,231
Server Two: 53,242

49231 is not correct and You can see this table with "~" mark in phpmyadmin