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With regards to SQL and queries, whats the difference between an in-memory table, temp table and a pivot table?
Started by barfoon on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Depends....
Alternatively, it's a table-valued variable, declared in a batch or function, with no persistence.
An in-memory table is a table that's been entirely cached, and so doesn't result in any physical (hard disk) reads when queried.
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I'm trying to find all the tables below my current node without also including the nested tables. In other words, if I have this, i want to find "yes" and not "no":
<table> <!-- outer table - no --> <tr><td> <div> <!--...
Started by Randal Schwartz on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
I think you want child::table aka table
#!/usr/bin/perl -- use strict; use warnings; use HTML; <!-- outer table - no --> <tr><td> <div> <!-- *** context node ) ); } ## end sub HTML::Element::addressx for....
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List the differences between the following MySql commands.
drop table tablename ; truncate table tablename ; delete from tablename where 1; Also from your experiences please tell me typical usage scenario for each.
Started by gameover on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
I check for that....
I would drop the table if I didn't need it anymore "Truncate operations drop and re-create the table, which is much faster than deleting rows one by one, particularly as a boolean value.
Drop is deleting the table.
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I have table A and table B, same schemas.
I want to insert certain rows from table A into table B. For example, insert into table B all rows from table A with column 'abc' > 10.
Couldn't figure out how to do it
Started by Saobi on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
To do it this way :
create table temp_B as select * from A where abc > 10 union select * from B; drop table B; rename temp_B to B;
If you have to insert millions+ rows, you could win several hours.
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First, I know that the sql statement to update table_a using values from table_b is in the form of:
Oracle:
UPDATE table_a SET (col1, col2) = (SELECT cola, colb FROM table_b WHERE table_a.key = table_b.key) WHERE EXISTS (SELECT * FROM table_b WHERE table...
Started by Lukman on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
How the engine determines what to do is based factors like indexes and statistics, the engine will have to to a "table scan" (roughly the equivalent of "iterate") to find the right sense that I feel stupid for using....
Ten rows in table b.
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How do you create a temporary table exactly like a current table in a stored procedure?
Started by craigmoliver on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Select * into #temp_table from current_table_in_stored_procedure #temp_table - locally temp ##temp_table - globally temp select top 0 * into #temp_table from current_table_in_stored_procedure to have empty ....
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Hi,
I need to drop a table and make a new one. If I drop the table and the table doesn't exist, I get an error
How can I check if the table exists?
I'm working on Oracle 11g
Thanks in advance.
Started by Gold on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
Something like
select count(*) from user_tables where table_name= :table name
or
select count(*) from dba_tables where owner = :table owner and table_name = :table name
or a heavy-handed alternative:
begin....
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I new to MySQL. I would like to copy the content of one table to another table within the same database. Basically, I would like to insert to a table from another table. Is there easy way of doing this?
thanks for any help
Started by Joneph O. on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
INSERT INTO TARGET_TABLE SELECT * FROM SOURCE_TABLE
EDIT: or if the tables have different structures you can also:
INSERT INTO TARGET_TABLE (col1,col2) SELECT col1,col2 FROM SOURCE_TABLE
If the table doesn't ....
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Hi Can somebody explain me the difference between Temp table and table variable in SQL server 2005?
Started by Prasad on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
There is a performance difference that favors table variables because temporary tables....
Hope these helps:
http://databases.aspfaq.com/database/should-i-use-a-temp-table-or-a-table
There are few differences you can check them here .
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What is main difference between INSERT INTO table VALUES .. and INSERT INTO table SET ?
Example:
INSERT INTO table (a, b, c) VALUES (1,2,3) INSERT INTO table SET a=1, b=2, c=3
And what about performance of these two?
Started by Irmantas on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
I think the extension is intended is "UPDATE table ....
SELECT form inserts rows selected from another table or tables.
VALUES ...
The INSERT ...
Refman/6.0/en/insert.html says:
INSERT inserts new rows into an existing table.
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