I have two tables,
TABLE A (id, some_data)
TABLE B (id, some_data)
Table A gets filled all the time, about 400 records / sec and there are lots of data that is
the same inside.
I need Table B that shows only unique data in it from Table A for a specific column.
My approach would be to have trigger (on insert) for Table A and check if that data is already present in Table B, if isn't just insert it there.
Can someone point for a better solution?
Thanks.
Related
I have 2 tables. First table is called Person. Second table is called PersonRule. Person table has much columns. But PersonRule has just 2 columns. In the person table, there is a column called ruleid. The column at the same time, there is in the PersonRule table. Is it possible, when i insert to data Person table, i want to automatically create a record in PersonRule table without trigger.?
And in PostgreSQL how can i do this.?
I would like to shift data from a specific paritioned table of parent to separate table.Can someone suggest what's the better way.
If I create a table
CREATE TABLE parent columns(a,b,c)partition by c
c Type is DATE.
CREATE TABLE dec_partition PARTITION OF parent FOR VALUES FROM '2021-02-12' to 2021-03-12;
Now I want to copy table dec_partition to separate table in single command with least time.
NOTE: The table has around 4million rows with 20 columns (1 of the column is in jsonb)
I have table location in postgres database with more then 50.000.000+ rows, and i decide to do partition!
Table parent have columns id,place and i want to do partition onplace column, with php and mysql i get all distinct places(about 300) and foreach
CREATE TABLE child_place_name (CHECK (place=place_name))INHERITS(location)
and after that in each child table
INSERT INTO child_place_name SELECT * FROM location WHERE place=place_name
and that works perfectly!
After i delete rows from parent class with
DELETE FROM location WHERE tableoid=('location'::regclass)::oid;
i that affected all rows is table!
Then i try to do query and a get times and realize that now is time for query 3 or more times longer then before.
I also have problem that my affect on speed: first i can't set primary key on id column in child tables, but i set index key on place(also index is set on place column in parent table), and also i can't set unique key on id and place columns i got error multiple parameters in not allowed(or something like that)
All i want is select side of table i don't need rules or triggers to set when i insert in parent table,cause that is another problem,only i want to know what is wrong with this approach!Maybe 300+ tables is to much?
How to clone or copy records in same table in PostgreSQL by creating temporary table.
trying to create clones of records from one table to the same table with changed name(which is basically composite key in that table).
You can do it all in one INSERT combined with a SELECT.
i.e. say you have the following table definition and data populated in it:
create table original
(
id serial,
name text,
location text
);
INSERT INTO original (name, location)
VALUES ('joe', 'London'),
('james', 'Munich');
And then you can INSERT doing the kind of switch you're talking about without using a TEMP TABLE, like this:
INSERT INTO original (name, location)
SELECT 'john', location
FROM original
WHERE name = 'joe';
Here's an sqlfiddle.
This should also be faster (although for tiny data sets probably not hugely so in absolute time terms), since it's doing only one INSERT and SELECT as opposed to an extra SELECT and CREATE TABLE plus an UPDATE.
Did a bit of research, came up with a logic :
Create temp table
Copy records into it
Update the records in temp table
Copy it back to original table
CREATE TEMP TABLE temporary AS SELECT * FROM ORIGINAL WHERE NAME='joe';
UPDATE TEMP SET NAME='john' WHERE NAME='joe';
INSERT INTO ORIGINAL SELECT * FROM temporary WHERE NAME='john';
Was wondering if there was any shorter way to do it.
Can anyone tell how to know one table is getting overlapped with another table (existing table) while inserting.
Assume I have already inserted Table1 and while inserting Table2, It is getting Overlapped with table1, But Code wise after inserting Table2, is there any way to check Table2 is Overlapping/Overridden on Table1?