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Optimise PostgreSQL for fast testing
...s should always be followed; see the version policy.
Don'ts
Do NOT put a tablespace on a RAMdisk or other non-durable storage.
If you lose a tablespace the whole database may be damaged and hard to use without significant work. There's very little advantage to this compared to just using UNLOGGED...
Generate table relationship diagram from existing schema (SQL Server) [closed]
Is there a way to produce a diagram showing existing tables and their relationships given a connection to a database?
9 Ans...
What is the difference between the Data Mapper, Table Data Gateway (Gateway), Data Access Object (DA
...
Your example terms; DataMapper, DAO, DataTableGateway and Repository, all have a similar purpose (when I use one, I expect to get back a Customer object), but different intent/meaning and resulting implementation.
A Repository "acts like a collection, except with m...
Counting the number of elements with the values of x in a vector
...
You can just use table():
> a <- table(numbers)
> a
numbers
4 5 23 34 43 54 56 65 67 324 435 453 456 567 657
2 1 2 2 1 1 2 1 2 1 3 1 1 1 1
Then you can subset it:
> a[names(a)==435]
4...
SQLAlchemy: cascade delete
...relationship doesn't dictate the parent-child setup. Using ForeignKey on a table is what sets it up as the child. It doesn't matter if the relationship is on the parent or child.
– d512
Aug 4 '16 at 2:04
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Select where count of one field is greater than one
...e result comparison.
Taking the query at face value:
SELECT *
FROM db.table
HAVING COUNT(someField) > 1
Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...
Is this in preparation for a unique cons...
Fastest way to flatten / un-flatten nested JSON objects
...object:
var flatten = (function (isArray, wrapped) {
return function (table) {
return reduce("", {}, table);
};
function reduce(path, accumulator, table) {
if (isArray(table)) {
var length = table.length;
if (length) {
var index ...
How to find a text inside SQL Server procedures / triggers?
...
Just be aware that the syscomments table stores the values in 8000-character chunks, so if you are unlucky enough to have the text you're searching for split across one of these boundaries, you won't find it with this method.
– ErikE
...
MySQL - UPDATE query based on SELECT Query
I need to check (from the same table) if there is an association between two events based on date-time.
11 Answers
...
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...