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Inner join vs Where
... for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.id;
SELECT *
FROM TABLE (DBMS_XPLAN.DISPLAY);
-- 0 select statement
-- 1 hash join (access("T1"."ID"="T2"."ID"))
-- 2 table access full table1
-- 3 table access ful...
Fetch the row which has the Max value for a column
... multiple rows for the userid where the maximum date is on multiple rows.
select userid,
my_date,
...
from
(
select userid,
my_date,
...
max(my_date) over (partition by userid) max_my_date
from users
)
where my_date = max_my_date
"Analytic functions rock"
Edi...
Add an already existing directory to a directory in Solution Explorer
...tory in Solution Explorer, but whenever I right-click on the directory and select Add => Existing Item , I can only add individual files, but not directories.
...
Reset auto increment counter in postgres
... Does anyone know why ALTER SEQUENCE product_id_seq RESTART WITH (SELECT MAX(id) from product); Doesn't work? The only way I found is to use two separate queries.
– Chris Huang-Leaver
Dec 20 '18 at 3:14
...
Get list of all tables in Oracle?
...
SELECT owner, table_name
FROM dba_tables
This is assuming that you have access to the DBA_TABLES data dictionary view. If you do not have those privileges but need them, you can request that the DBA explicitly grants you...
SQL JOIN vs IN performance?
...king, IN and JOIN are different queries that can yield different results.
SELECT a.*
FROM a
JOIN b
ON a.col = b.col
is not the same as
SELECT a.*
FROM a
WHERE col IN
(
SELECT col
FROM b
)
, unless b.col is unique.
However, this is the syno...
Login failed for user 'IIS APPPOOL\ASP.NET v4.0'
....
In SSMS, under the server, expand Security, then right click Logins and select "New Login...".
In the New Login dialog, enter the app pool as the login name and click "OK".
You can then right click the login for the app pool, select Properties and select "User Mapping". Check the appropriate...
MySQL - force not to use cache for testing speed of query
...ACHE (MySQL 5.7) option in your query.
(MySQL 5.6 users click HERE )
eg.
SELECT SQL_NO_CACHE * FROM TABLE
This will stop MySQL caching the results, however be aware that other OS and disk caches may also impact performance. These are harder to get around.
...
Importing a GitHub project into Eclipse
...ries")
Eclipse with GitHub
EGit tutorial
Copy the URL from GitHub and select in Eclipse from the menu the
File → Import → Git → Projects from Git
If the Git repo isn't cloned yet:
In> order to checkout a remote project, you will have to clone its repository first.
Open the E...
How do I limit task tags to current project in Eclipse?
...gure the scope.
Down arrow at the top right -> Configure Contents:
Select a configuration on the left (or create a new one) and on the right in the Scope section select "On any element in same project".
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