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How to determine CPU and memory consumption from inside a process?
... at /proc/self/status, which looks like this:
Name: whatever
State: S (sleeping)
Tgid: 19340
Pid: 19340
PPid: 19115
TracerPid: 0
Uid: 0 0 0 0
Gid: 0 0 0 0
FDSize: 256
Groups: 0 1 2 3 4 6 10 11 20 26 27
VmPeak: 676252 kB
VmSize: 651352 kB
...
Oracle Differences between NVL and Coalesce
...the first non-NULL (there are some exceptions, such as sequence NEXTVAL):
SELECT SUM(val)
FROM (
SELECT NVL(1, LENGTH(RAWTOHEX(SYS_GUID()))) AS val
FROM dual
CONNECT BY
level <= 10000
)
This runs for almost 0.5 seconds, since it generates...
Is there a way to access the “previous row” value in a SELECT statement?
...d to order by some column for this to be meaningful. Something like this:
select t1.value - t2.value from table t1, table t2
where t1.primaryKey = t2.primaryKey - 1
If you know how to order things but not how to get the previous value given the current one (EG, you want to order alphabetically) ...
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...
SELECT DISTINCT on one column
...ou're on SQL Server 2005 or greater, you can use a CTE with ROW_NUMBER():
SELECT *
FROM (SELECT ID, SKU, Product,
ROW_NUMBER() OVER (PARTITION BY PRODUCT ORDER BY ID) AS RowNumber
FROM MyTable
WHERE SKU LIKE 'FOO%') AS a
WHERE a.RowNumber = 1
...
How to use OpenFileDialog to select a folder?
How to use OpenFileDialog to select folders?
8 Answers
8
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What is the difference D3 datum vs. data?
...rs here on SO are not complete as they only cover the case when you invoke selection.data and selection.datum with an input data parameter. Even in that scenario, the two behave differently if the selection is a single element versus when it contains multiple elements. Moreover, both of these method...
Insert into … values ( SELECT … FROM … )
...
Try:
INSERT INTO table1 ( column1 )
SELECT col1
FROM table2
This is standard ANSI SQL and should work on any DBMS
It definitely works for:
Oracle
MS SQL Server
MySQL
Postgres
SQLite v3
Teradata
DB2
Sybase
Vertica
HSQLDB
H2
AWS RedShift
SA...
Import / Export database with SQL Server Server Management Studio
... if you want to also export the data, on the "Set Scripting Options" step, select the "Advanced" button and change "Types of data to script" from "Schema Only" to "Data Only" or "Schema and Data".
share
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mysql -> insert into tbl (select from another table) and some default values [duplicate]
As the title says, I am trying to insert into one table selecting values from another table and some default values.
5 Ans...