I want to get a list of information of active queries that are running in my SQL Server (in order to kill a few of those queries).
I want a query to get this required information:
| query_id (if possible) | query_text | query_start_time | time_elapsed | host_name | user_group | query_status |
I am new to SQL Server please suggest....
Try this
select
r.session_id,
r.status,
r.command,
r.cpu_time,
r.total_elapsed_time,
t.text
from sys.dm_exec_requests as r
cross apply sys.dm_exec_sql_text(r.sql_handle) as t
Related
I have the following SQL query:
SELECT TOP 3 accounts.username
,COUNT(accounts.username) AS count
FROM relationships
JOIN accounts ON relationships.account = accounts.id
WHERE relationships.following = 4
AND relationships.account IN (
SELECT relationships.following
FROM relationships
WHERE relationships.account = 8
);
I want to return the total count of accounts.username and the first 3 accounts.username (in no particular order). Unfortunately accounts.username and COUNT(accounts.username) cannot coexist. The query works fine removing one of the them. I don't want to send the request twice with different select bodies. The count column could span to 1000+ so I would prefer to calculate it in SQL rather in code.
The current query returns the error Column 'accounts.username' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. which has not led me anywhere and this is different to other questions as I do not want to use the 'group by' clause. Is there a way to do this with FOR JSON AUTO?
The desired output could be:
+-------+----------+
| count | username |
+-------+----------+
| 1551 | simon1 |
| 1551 | simon2 |
| 1551 | simon3 |
+-------+----------+
or
+----------------------------------------------------------------+
| JSON_F52E2B61-18A1-11d1-B105-00805F49916B |
+----------------------------------------------------------------+
| [{"count": 1551, "usernames": ["simon1", "simon2", "simon3"]}] |
+----------------------------------------------------------------+
If you want to display the total count of rows that satisfy the filter conditions (and where username is not null) in an additional column in your resultset, then you could use window functions:
SELECT TOP 3
a.username,
COUNT(a.username) OVER() AS cnt
FROM relationships r
JOIN accounts a ON r.account = a.id
WHERE
r.following = 4
AND EXISTS (
SELECT 1 FROM relationships t1 WHERE r1.account = 8 AND r1.following = r.account
)
;
Side notes:
if username is not nullable, use COUNT(*) rather than COUNT(a.username): this is more efficient since it does not require the database to check every value for nullity
table aliases make the query easier to write, read and maintain
I usually prefer EXISTS over IN (but here this is mostly a matter of taste, as both techniques should work fine for your use case)
I'm trying to retrieve all(*) columns from a MongoDB object with Apache Drill expression SQL:
`_id`.`$oid`
Background: I'm using Apache Drill to query MongoDB collections. By default, Drill retrieves the ObjectId values in a different format than the stored in the database. For example:
Mongo: ObjectId(“59f2c3eba83a576fe07c735c”)
Drill query result: [B#3149a…]
In order to get the data in String format (59f2c3eba83a576fe07c735c) from the object, I changed the Drill config "store.mongo.bson.record.reader" to "false".
ALTER SESSION SET store.mongo.bson.record.reader = false
Drill query result after config set to false:
select * from calc;
+--------------------------------------+---------+
| _id | name |
+--------------------------------------+---------+
| {"$oid":"5cb0e161f0849231dfe16d99"} | thiago |
+--------------------------------------+---------+
Running a query by _id:
select `o`.`_id`.`$oid` , `o`.`name` from mongo.od_teste.calc o where `o`.`_id`.`$oid`='5cb0e161f0849231dfe16d99';
Result:
+---------------------------+---------+
| EXPR$0 | name |
+---------------------------+---------+
| 5cb0e161f0849231dfe16d99 | thiago |
+---------------------------+---------+
For an object with a few columns like the one above (_id, name) it's ok to specify all the columns in the select query by id. However, in my production database, the objects have a "hundred" of columns.
If I try to query all (*) columns from the collection, this is the result:
select `o`.* from mongo.od_teste.calc o where `o`.`_id`.`$oid`='5cb0e161f0849231dfe16d99';
or
select * from mongo.od_teste.calc o where `o`.`_id`.`$oid`='5cb0e161f0849231dfe16d99';
+-----+
| ** |
+-----+
+-----+
No rows selected (6.112 seconds)
Expected result: Retrieve all columns from a MongoDB collection instead of declaring all of them on the SQL query.
I have no suggestions here, because it is a bug in Mongo Storage Plugin.
I have created Jira ticket for it, please take a look and feel free to add any related info there: DRILL-7176
I am working on a query that will fetch multipart messages from 2 tables. However, it only works IF there are multiple parts. If there is only a one part message then the the join condition won't be true anymore. How could I make it to work for both single and multipart messages?
Right now it fails if there is an entry in outbox and nothing in outbox_multipart.
My first table is "outbox" that looks like this.
TextDecoded | ID | CreatorID
Helllo, m.. | 123 | Martin
Yes, I wi.. | 124 | Martin
My second table is "outbox_multipart" that looks very similar.
TextDecoded | ID | SequencePosition
my name i.. | 123 | 2
s Martin. | 123 | 3
ll do tha.. | 124 | 2
t tomorrow. | 124 | 3
My query so far
SELECT
CONCAT(ob.TextDecoded,
GROUP_CONCAT(obm.TextDecoded
ORDER BY obm.SequencePosition ASC
SEPARATOR ''
)
) AS TextDecoded,
ob.ID,
ob.creatorID
FROM outbox AS ob
JOIN outbox_multipart AS obm ON obm.ID = ob.ID
GROUP BY
ob.ID,
ob.creatorID
Use a left join instead of an (implicit) inner join. Then, also use COALESCE on the TextDecoded alias to make sure that empty string (and not NULL) appears in the expected output.
SELECT
CONCAT(ob.TextDecoded,
COALESCE(GROUP_CONCAT(obm.TextDecoded
ORDER BY obm.SequencePosition
SEPARATOR ''), '')) AS TextDecoded,
ob.ID,
ob.creatorID
FROM outbox AS ob
LEFT JOIN outbox_multipart AS obm
ON obm.ID = ob.ID
GROUP BY
ob.ID,
ob.creatorID,
ob.TextDecoded;
Note: Strictly speaking, outbox.TextDecoded should also appear in the GROUP BY clause, since it is not an aggregate. I have made this change in the query.
What is the command to find the size of all the databases?
I am able to find the size of a specific database by using following command:
select pg_database_size('databaseName');
You can enter the following psql meta-command to get some details about a specified database, including its size:
\l+ <database_name>
And to get sizes of all databases (that you can connect to):
\l+
You can get the names of all the databases that you can connect to from the "pg_datbase" system table. Just apply the function to the names, as below.
select t1.datname AS db_name,
pg_size_pretty(pg_database_size(t1.datname)) as db_size
from pg_database t1
order by pg_database_size(t1.datname) desc;
If you intend the output to be consumed by a machine instead of a human, you can cut the pg_size_pretty() function.
-- Database Size
SELECT pg_size_pretty(pg_database_size('Database Name'));
-- Table Size
SELECT pg_size_pretty(pg_relation_size('table_name'));
Based on the answer here by #Hendy Irawan
Show database sizes:
\l+
e.g.
=> \l+
berbatik_prd_commerce | berbatik_prd | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 19 MB | pg_default |
berbatik_stg_commerce | berbatik_stg | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 8633 kB | pg_default |
bursasajadah_prd | bursasajadah_prd | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 1122 MB | pg_default |
Show table sizes:
\d+
e.g.
=> \d+
public | tuneeca_prd | table | tomcat | 8192 bytes |
public | tuneeca_stg | table | tomcat | 1464 kB |
Only works in psql.
Yes, there is a command to find the size of a database in Postgres. It's the following:
SELECT pg_database.datname as "database_name", pg_size_pretty(pg_database_size(pg_database.datname)) AS size_in_mb FROM pg_database ORDER by size_in_mb DESC;
SELECT pg_size_pretty(pg_database_size('name of database'));
Will give you the total size of a particular database however I don't think you can do all databases within a server.
However you could do this...
DO
$$
DECLARE
r RECORD;
db_size TEXT;
BEGIN
FOR r in
SELECT datname FROM pg_database
WHERE datistemplate = false
LOOP
db_size:= (SELECT pg_size_pretty(pg_database_size(r.datname)));
RAISE NOTICE 'Database:% , Size:%', r.datname , db_size;
END LOOP;
END;
$$
From the PostgreSQL wiki.
NOTE: Databases to which the user cannot connect are sorted as if they were infinite size.
SELECT d.datname AS Name, pg_catalog.pg_get_userbyid(d.datdba) AS Owner,
CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')
THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))
ELSE 'No Access'
END AS Size
FROM pg_catalog.pg_database d
ORDER BY
CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')
THEN pg_catalog.pg_database_size(d.datname)
ELSE NULL
END DESC -- nulls first
LIMIT 20
The page also has snippets for finding the size of your biggest relations and largest tables.
Start pgAdmin, connect to the server, click on the database name, and select the statistics tab. You will see the size of the database at the bottom of the list.
Then if you click on another database, it stays on the statistics tab so you can easily see many database sizes without much effort. If you open the table list, it shows all tables and their sizes.
You can use below query to find the size of all databases of PostgreSQL.
Reference is taken from this blog.
SELECT
datname AS DatabaseName
,pg_catalog.pg_get_userbyid(datdba) AS OwnerName
,CASE
WHEN pg_catalog.has_database_privilege(datname, 'CONNECT')
THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(datname))
ELSE 'No Access For You'
END AS DatabaseSize
FROM pg_catalog.pg_database
ORDER BY
CASE
WHEN pg_catalog.has_database_privilege(datname, 'CONNECT')
THEN pg_catalog.pg_database_size(datname)
ELSE NULL
END DESC;
du -k /var/lib/postgresql/ |sort -n |tail
I have inherited an application that logs the results of certain daily commands that run on multiple hosts to an MS-SQL table. Now I've been asked to provide a view/query that displays the last log line per host to get an overview of the last results.
The table is similar to this:
------------------------------
|HOST |LAST_RUN |RESULT |
------------------------------
|SERVER1 |13-07-2009 |OK |
|SERVER2 |13-07-2009 |Failed |
|SERVER1 |12-07-2009 |OK |
|SERVER2 |12-07-2009 |OK |
|SERVER3 |11-07-2009 |OK |
------------------------------
In this case the query should output:
------------------------------
|HOST |LAST_RUN |RESULT |
------------------------------
|SERVER1 |13-07-2009 |OK |
|SERVER2 |12-07-2009 |Failed |
|SERVER3 |11-07-2009 |OK |
------------------------------
...as these are the last lines for each of the hosts.
I realise that it might be something simple I'm missing, but I just can't seem to get it right :-(
Thanks,
Mark.
Here's a quick version:
SELECT lt.Host, lt.Last_Run, lt.Results
from LogTable lt
inner join (select Host, max(Last_Run) Last_Run
from LogTable
group by Host) MostRecent
on MostRecent.Host = lt.Host
and MostRecent.Last_run = lt.Last_Run
This should work in most any SQL system. The ranking functions in SQL Server 2005 or 2008 might work a bit better.
Select Host, Last_Run, Result from
(
select ROW_NUMBER() OVER (PARTITION BY Host ORDER BY Last_Run DESC) AS row_number,
Host, Last_Run, Result from Table1
) tempTable
where row_number = 1
select host, max (last_run) from t group by host
Gets you the host and last_run you want. Then
(select host as h, last_run as lr, result as r from t) inner join (select host as h_max, max (last_run) as lr_max from t group by host) on h=h_max, lr=lr_max
Forgive my sql if not exact -- not trying it or looking it up, but you get the idea.
I think there's a typo at SERVER2's LAST_RUN date.
This provides the same result as all the other great answers without the use of a subquery:
select t."HOST"
, t."LAST_RUN"
, t."RESULT"
from yourtable t
left outer join yourtable t2
on t."HOST" = t2."HOST"
and
t2."LAST_RUN" > t."LAST_RUN"
where t2."RESULT" is null;
And the resultset looks like this:
|HOST |LAST_RUN |RESULT |
------------------------------
|SERVER1 |13-07-2009 |OK |
|SERVER2 |13-07-2009 |Failed |
|SERVER3 |11-07-2009 |OK |