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How do I grant myself admin access to a local SQL Server instance?
...he "SQL Server Configuration Manager", right click the server instance and select properties, go to the tab "Startup Parameters" and add -m.
– maets
May 5 '15 at 13:32
...
What is the difference between Views and Materialized Views in Oracle?
... you. The downside of a view is that its performance depends on how good a select statement the view is based on. If the select statement used by the view joins many tables, or uses joins based on non-indexed columns, the view could perform poorly.
Materialized views
They are similar to regular vi...
Is having an 'OR' in an INNER JOIN condition a bad idea?
... a MERGE JOIN.
It can be expressed as a concatenation of two resultsets:
SELECT *
FROM maintable m
JOIN othertable o
ON o.parentId = m.id
UNION
SELECT *
FROM maintable m
JOIN othertable o
ON o.id = m.parentId
, each of them being an equijoin, however, SQL Server's optimiz...
Explain ExtJS 4 event handling
...js4.1)
Lets say we have a controller Station (Sencha MVC examples) with a select box:
Ext.define('Pandora.controller.Station', {
extend: 'Ext.app.Controller',
...
init: function() {
this.control({
'stationslist': {
selectionchange: this.onStationSel...
MYSQL OR vs IN performance
...for future Googlers. Total count of returned results is 7264 out of 10000
SELECT * FROM item WHERE id = 1 OR id = 2 ... id = 10000
This query took 0.1239 seconds
SELECT * FROM item WHERE id IN (1,2,3,...10000)
This query took 0.0433 seconds
IN is 3 times faster than OR
...
How do I temporarily disable triggers in PostgreSQL?
...ct = 'disable';
else
act = 'enable';
end if;
for r in select c.relname from pg_namespace n
join pg_class c on c.relnamespace = n.oid and c.relhastriggers = true
where n.nspname = nsp
loop
execute format('alter table %I %s trigger all', r.relname, act)...
live output from subprocess command
...ptimization: If we are only using one pipe, or no pipe at
# all, using select() or threads is unnecessary.
if [self.stdin, self.stdout, self.stderr].count(None) >= 2:
But, alas, here we've made at least two, and maybe three, different pipes, so the count(None) returns either 1 or 0. We...
Using backticks around field names
...backticks, I would assume it lets you get away with ridiculous stuff like
SELECT `id`, `my name`, `another field` , `field,with,comma`
Which does of course generate badly named tables.
If you're just being concise I don't see a problem with it,
you'll note if you run your query as such
EXPLA...
How do you search an amazon s3 bucket?
...to access many nodes at once ala more traditional datastores that offer a (SELECT * FROM ... WHERE ...) (in a SQL model).
What you will need to do is perform ListBucket to get a listing of objects in the bucket and then iterate over every item performing a custom operation that you implement - whic...
How to fix/convert space indentation in Sublime Text?
...> Indentation
It should read:
Indent using spaces [x]
Tab width: 2
Select:
Convert Indentation to Tabs
Then Select:
Tab width: 4
Convert Indentation to Spaces
Done.
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