大约有 40,000 项符合查询结果（耗时：0.0392秒） [XML]
MySQL select 10 random rows from 600K rows fast
...s 0.35s on my machine.
This is fast because the sort phase only uses the indexed ID column. You can see this behaviour in the explain:
SELECT * FROM tbl ORDER BY RAND() LIMIT 10:
SELECT * FROM tbl AS t1 JOIN (SELECT id FROM tbl ORDER BY RAND() LIMIT 10) as t2 ON t1.id=t2.id
Weighted Version: ...
Unsafe JavaScript attempt to access frame with URL
...
From a child document of different origin you are not allowed access to the top window's location.hash property, but you are allowed to set the location property itself.
This means that given that the top windows location is http://example.com/page/, instead of doing
parent.lo...
What are the best practices for catching and re-throwing exceptions?
...don't know how to respond to the failure
}
PHP 5.5 has introduced the finally keyword, so for cleanup scenarios there is now another way to approach this. If the cleanup code needs to run no matter what happened (i.e. both on error and on success) it's now possible to do this while transparently a...
SQL Server Index Naming Conventions [closed]
Is there some standard way to name indexes for SQL Server? It seems that the primary key index is named PK_ and non-clustered indexes typically start with IX_. Are there any naming conventions beyond that for unique indexes?
...
Delete all documents from index/type without deleting type
...option will delete the type and its mappings. So don't forget to remap the index type after deleting. Or else you will be messed up.
– Finny Abraham
Sep 15 '15 at 6:14
24
...
ElasticSearch: Unassigned Shards, how to fix?
...n.
# v0.90.x and earlier
curl -XPUT 'localhost:9200/_settings' -d '{
"index.routing.allocation.disable_allocation": false
}'
# v1.0+
curl -XPUT 'localhost:9200/_cluster/settings' -d '{
"transient" : {
"cluster.routing.allocation.enable" : "all"
}
}'
Elasticsearch will then re...
How to repair a serialized string which has been corrupted by an incorrect byte count length?
...en ( $data2 )) ? strlen ( $data1 ) : strlen ( $data2 );
echo $data1 . PHP_EOL;
echo $data2 . PHP_EOL;
for($i = 0; $i < $max; $i ++) {
if (@$data1 {$i} !== @$data2 {$i}) {
echo "Diffrence ", @$data1 {$i}, " != ", @$data2 {$i}, PHP_EOL;
echo "\t-> ...
PHP prepend associative array with literal keys?
... See also array_merge() and its difference from using the + operator: br.php.net/manual/en/function.array-merge.php#92602
– Havenard
Sep 3 '09 at 1:33
2
...
How to get distinct values from an array of objects in JavaScript?
...": "Carl", "age": 35 }
];
array.map(item => item.age)
.filter((value, index, self) => self.indexOf(value) === index)
> [17, 35]
share
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improve this answer
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fol...
AngularJS routing without the hash '#'
...:
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} !^(/index\.php|/img|/js|/css|/robots\.txt|/favicon\.ico)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ./index.html [L]
Users will be directed to the your app when they enter a ...