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ORA-30926: unable to get a stable set of rows in the source tables
...uplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times.
You could quickly solve the problem by using a DISTINCT in your query (in fact, if 'Y' is a constant value you don't even need to put it in the query).
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MySQL maximum memory usage
...the (f'ing) manual.
As for the database -- a few important constraints:
table engine (InnoDB, MyISAM, ...)
size
indices
usage
Most MySQL tips on stackoverflow will tell you about 5-8 so called important settings. First off, not all of them matter - e.g. allocating a lot of resources to InnoDB a...
Auto increment in phpmyadmin
... column. I guess the phpMyAdmin version is 3.5.5 but not sure.
Click on Table > Structure tab > Under Action
Click Primary (set as primary),
click on Change on the pop-up window, scroll left and check A_I. Also make sure you have selected None for Default
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Oracle: how to UPSERT (update or insert into a table?)
The UPSERT operation either updates or inserts a row in a table, depending if the table already has a row that matches the data:
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What do Clustered and Non clustered index actually mean?
... all the columns. You do not have to go first to the index and then to the table.
Writing to a table with a clustered index can be slower, if there is a need to rearrange the data.
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Fastest way to count exact number of rows in a very large table?
I have come across articles that state that SELECT COUNT(*) FROM TABLE_NAME will be slow when the table has lots of rows and lots of columns.
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How to version control a record in a database
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Let's say you have a FOO table that admins and users can update. Most of the time you can write queries against the FOO table. Happy days.
Then, I would create a FOO_HISTORY table. This has all the columns of the FOO table. The primary key is th...
【可动态编辑表格】App Inventor 2 Dynamic Editable HTML Table - App应用...
...lay an AI2 (in csv format e.g. header row, then data rows) list in an html table. It will also allow you (with the exception of the header row) to create new rows, edit any row, and delete any row, whilst returning the saved/updated data to your app, you therefore have a full CRUD.
[co...
Reset auto increment counter in postgres
I would like to force the auto increment field of a table to some value, I tried with this:
12 Answers
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When should I use cross apply over inner join?
...readable and probably less efficient.
Update:
Just checked.
master is a table of about 20,000,000 records with a PRIMARY KEY on id.
This query:
WITH q AS
(
SELECT *, ROW_NUMBER() OVER (ORDER BY id) AS rn
FROM master
),
t AS
(
SELEC...