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Can PostgreSQL index array columns?
...e to use the array operators and the GIN-index type.
Example:
CREATE TABLE "Test"("Column1" int[]);
INSERT INTO "Test" VALUES ('{10, 15, 20}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Column1");
-- To enforce index usage because...
How do I kill all the processes in Mysql “show processlist”?
...<USERNAME> -p<PASSWORD>
mysqladmin processlist will print a table with the thread ids;
awk will parse from the second column only the numbers (thread ids) and generate MySQL KILL commands;
and finally the last call to mysql will execute the passed commands.
You can run grep before t...
How do I format a number with commas in T-SQL?
...p_spaceused in SQL Server 2008 to look at data/index space ratios of some tables in my database. Of course I am getting all sorts of large numbers in the results and my eyes are starting to gloss over. It would be really convenient if I could format all those numbers with commas (987654321 become...
Determine whether an array contains a value [duplicate]
...oject and nowadays it's Babel :) big win for JavaScript community! There's table of what's available of ES7 already on many platforms including babel pollyfils kangax.github.io/compat-table/es2016plus
– Lukas Liesis
Jul 12 '16 at 9:52
...
Paste multiple columns together
...# 3 3 c-f-i
Alternatively we could update data in place using the data.table package (assuming fresh data)
library(data.table)
setDT(data)[, x := Reduce(function(...) paste(..., sep = "-"), .SD[, mget(cols)])]
data[, (cols) := NULL]
data
# a x
# 1: 1 a-d-g
# 2: 2 b-e-h
# 3: 3 c-f-i
Ano...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
If I have a table
15 Answers
15
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Chrome Extension how to send data from content script to popup.html
...tyle="font-weight:bold; text-align:center;">DOM Info</h3>
<table border="1" cellpadding="3" style="border-collapse:collapse;">
<tr>
<td nowrap>Total number of elements:</td>
<td align="right"><span id="total">N/A</span><...
WCF vs ASP.NET Web API [closed]
...
this table is meaningless. "JQuery" (scare quotes for the capital J) is a protocol and/or format?
– hyankov
Sep 2 '17 at 18:39
...
DbEntityValidationException - How can I easily tell what caused the error?
...k whether the property's value is out of range, like when you designed the table. Table_Column_UserName is varchar(20). But, in EF, you entered a value that longer than 20.
Or, in other cases, if the column does not allow to be a Null.
So, in the validation process, you have to set a value to the n...
Comparing date ranges
... |-----| equal start with end of comparison period
If your table has columns called range_end and range_start, here's some simple SQL to retrieve all the matching rows:
SELECT *
FROM periods
WHERE NOT (range_start > @check_period_end
OR range_end < @check_period_s...