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Why use the INCLUDE clause when creating an index?
...ot in the WHERE/JOIN/GROUP BY/ORDER BY, but only in the column list in the SELECT clause.
The INCLUDE clause adds the data at the lowest/leaf level, rather than in the index tree.
This makes the index smaller because it's not part of the tree
INCLUDE columns are not key columns in the index, so th...
Postgresql 9.2 pg_dump version mismatch
...ll PostgreSQL 9.2.1 in the pg_dump client machine or just copy the $PGHOME from the PostgreSQL server machine to the client machine. Note that there is no need to initdb a new cluster in the client machine.
After you have finished installing the 9.2.1 software, remember to edit some environment var...
Getting attribute using XPath
...e), for
the first element?
Use:
/*/book[1]/title/@lang
This means:
Select the lang attribute of the title element that is a child of the first book child of the top element of the XML document.
To get just the string value of this attribute use the standard XPath function string():
string(...
How to change Xcode Project name
...
For Xcode 4 or later:
Open a project
Select Project Navigator
Highlight project name
Single click on project name
For Xcode 3:
Open a project > Menu > Project > Rename ...
...
SQL - Rounding off to 2 decimal places
...
Could you not cast your result as numeric(x,2)? Where x <= 38
select
round(630/60.0,2),
cast(round(630/60.0,2) as numeric(36,2))
Returns
10.500000 10.50
share
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improve ...
Cartesian product of x and y array points into single array of 2D points
... I haven't noticed any case where this approach produces different results from those produced by meshgrid + dstack. Could you post an example?
– senderle
Jul 16 '17 at 22:26
...
Psql list all tables
...This is where the INFORMATION_SCHEMA comes to the rescue. To list tables:
SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';
BTW, if you ever want to see what psql is doing in response to a backslash command, run psql with the -E flag. eg:
$ psql -E regress
regre...
Postgres: Distinct but only for one column
...h names (having more than 1 mio. rows), but I have also many duplicates. I select 3 fields: id , name , metadata .
3 Ans...
Restore LogCat window within Android Studio
...e bottom). Use the "gear" at the extreme top right of the log cat section; select floating mode. Confusingly it then "appears to be docked" still ... just grab the bar and move it around. (If you're used to Mac, it's a little confusing.) (Android Studio is awesome on Mac eh??)
...
What is the benefit of zerofill in MySQL?
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When you select a column with type ZEROFILL it pads the displayed value of the field with zeros up to the display width specified in the column definition. Values longer than the display width are not truncated. Note that usage of ZER...