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What is InnoDB and MyISAM in MySQL?
...er on their locking implementation: InnoDB locks the particular row in the table, and MyISAM locks the entire MySQL table.
You can specify the type by giving MYISAM OR InnoDB while creating a table in DB.
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Computed / calculated / virtual / derived columns in PostgreSQL
...enerated columns are introduced with Postgres 12. Trivial example:
CREATE TABLE tbl (
int1 int
, int2 int
, product bigint GENERATED ALWAYS AS (int1 * int2) STORED
);
db<>fiddle here
VIRTUAL generated columns may come with one of the next iterations. (Not in Postgres 13, yet) .
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MySQL - why not index every field?
...n called), so it could potentially slow read operations as well (for large tables).
Check this out
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Does Firefox support position: relative on table elements?
...the answer for me as well. display: block isn't enough of a fix on complex table layouts. The extra div is solution that is more reliable.
– DA.
Apr 18 '12 at 4:49
5
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Add a column to a table, if it does not already exist
I want to write a query for MS SQL Server that adds a column into a table. But I don't want any error display, when I run/execute the following query.
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How do I see what character set a MySQL database / table / column is?
... FROM information_schema.SCHEMATA
WHERE schema_name = "schemaname";
For Tables:
SELECT CCSA.character_set_name FROM information_schema.`TABLES` T,
information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
WHERE CCSA.collation_name = T.table_collation
AND T.table_schema = "schemana...
MyISAM versus InnoDB [closed]
...
I have briefly discussed this question in a table so you can conclude whether to go with InnoDB or MyISAM.
Here is a small overview of which db storage engine you should use in which situation:
MyISAM InnoDB
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How do you delete a column by name in data.table?
...
Any of the following will remove column foo from the data.table df3:
# Method 1 (and preferred as it takes 0.00s even on a 20GB data.table)
df3[,foo:=NULL]
df3[, c("foo","bar"):=NULL] # remove two columns
myVar = "foo"
df3[, (myVar):=NULL] # lookup myVar contents
# Method 2a ...
Wrap text in tag
...
To Wrap TD text
First set table style
table{
table-layout: fixed;
}
then set TD Style
td{
word-wrap:break-word
}
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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 ...