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How do you find the disk size of a Postgres / PostgreSQL table and its indexes
I'm coming to Postgres from Oracle and looking for a way to find the table and index size in terms of bytes/MB/GB/etc , or even better the size for all tables. In Oracle I had a nasty long query that looked at user_lobs and user_segments to give back an answer.
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jquery - fastest way to remove all rows from a very large table
I thought this might be a fast way to remove the contents of a very large table (3000 rows):
8 Answers
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How to list of all the tables defined for the database when using active record?
How do I get a list of all the tables defined for the database when using active record?
5 Answers
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CROSS JOIN vs INNER JOIN in SQL
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Cross join does not combine the rows, if you have 100 rows in each table with 1 to 1 match, you get 10.000 results, Innerjoin will only return 100 rows in the same situation.
These 2 examples will return the same result:
Cross join
select * from table1 cross join table2 where table1.id = ...
What is the difference between “INNER JOIN” and “OUTER JOIN”?
... the outer parts of a Venn diagram union.
Examples
Suppose you have two tables, with a single column each, and data as follows:
A B
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1 3
2 4
3 5
4 6
Note that (1,2) are unique to A, (3,4) are common, and (5,6) are unique to B.
Inner join
An inner join using either of the...
How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...ions:
Individual insert/update operations in a retry loop; or
Locking the table and doing batch merge
Individual row retry loop
Using individual row upserts in a retry loop is the reasonable option if you want many connections concurrently trying to perform inserts.
The PostgreSQL documentation co...
Is there an expression for an infinite generator?
...i*step for i, _ in enumerate(iter(int, 1)))
– Coffee_Table
Aug 13 '18 at 23:43
2
Just to explain ...
Search of table names
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I'm using this and works fine
SELECT * FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME LIKE '%%'
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json_encode is returning NULL?
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few day ago I have the SAME problem with 1 table.
Firstly try:
echo json_encode($rows);
echo json_last_error(); // returns 5 ?
If last line returns 5, problem is with your data. I know, your tables are in UTF-8, but not entered data. For example the input was i...
Reset identity seed after deleting records in SQL Server
I have inserted records into a SQL Server database table. The table had a primary key defined and the auto increment identity seed is set to “Yes”. This is done primarily because in SQL Azure, each table has to have a primary key and identity defined.
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