What would happen if I run two SQL commands using the same DB connection?
I'm writing a program to run mass calculation and output results into PostgreSQL.
My platform is Windows Sever 2008, PostgreSQL 10. My program is written in C.
The results would be produced group by group, finishing of each group will create an extra thread to write the output.
Now since the output threads are created one by one, it is possible that two or more SQL input commands will be created simultaneously, or the previous one is under process when new ones call the function.
So my questions are:
(1) What would happen if one thread is in SQL processing and another thread called PQexec(PGconn *conn, const char *query), would they effect each other?
(2) What if I apply different PGconn? Would it speed up?
postgresql
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
add a comment |
I'm writing a program to run mass calculation and output results into PostgreSQL.
My platform is Windows Sever 2008, PostgreSQL 10. My program is written in C.
The results would be produced group by group, finishing of each group will create an extra thread to write the output.
Now since the output threads are created one by one, it is possible that two or more SQL input commands will be created simultaneously, or the previous one is under process when new ones call the function.
So my questions are:
(1) What would happen if one thread is in SQL processing and another thread called PQexec(PGconn *conn, const char *query), would they effect each other?
(2) What if I apply different PGconn? Would it speed up?
postgresql
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
add a comment |
I'm writing a program to run mass calculation and output results into PostgreSQL.
My platform is Windows Sever 2008, PostgreSQL 10. My program is written in C.
The results would be produced group by group, finishing of each group will create an extra thread to write the output.
Now since the output threads are created one by one, it is possible that two or more SQL input commands will be created simultaneously, or the previous one is under process when new ones call the function.
So my questions are:
(1) What would happen if one thread is in SQL processing and another thread called PQexec(PGconn *conn, const char *query), would they effect each other?
(2) What if I apply different PGconn? Would it speed up?
postgresql
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
I'm writing a program to run mass calculation and output results into PostgreSQL.
My platform is Windows Sever 2008, PostgreSQL 10. My program is written in C.
The results would be produced group by group, finishing of each group will create an extra thread to write the output.
Now since the output threads are created one by one, it is possible that two or more SQL input commands will be created simultaneously, or the previous one is under process when new ones call the function.
So my questions are:
(1) What would happen if one thread is in SQL processing and another thread called PQexec(PGconn *conn, const char *query), would they effect each other?
(2) What if I apply different PGconn? Would it speed up?
postgresql
postgresql
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
edited Nov 15 '18 at 6:06
Laurenz Albe
49k102848
49k102848
asked Nov 15 '18 at 5:50
ShoreShore
748
asked Nov 15 '18 at 5:50
ShoreShore
748
asked Nov 15 '18 at 5:50
ShoreShore
748
748
add a comment |
add a comment |
1 Answer
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If you try to call PQexec on a connection that is in the process of executing an SQL statement, you would cause a protocol violation. That just doesn't work.
Processing could certainly be made faster if you use several database connections in parallel — concurrent transactions is something that PostgreSQL is designed for.
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
add a comment |
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1 Answer
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active
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
If you try to call PQexec on a connection that is in the process of executing an SQL statement, you would cause a protocol violation. That just doesn't work.
Processing could certainly be made faster if you use several database connections in parallel — concurrent transactions is something that PostgreSQL is designed for.
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
add a comment |
If you try to call PQexec on a connection that is in the process of executing an SQL statement, you would cause a protocol violation. That just doesn't work.
Processing could certainly be made faster if you use several database connections in parallel — concurrent transactions is something that PostgreSQL is designed for.
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
add a comment |
If you try to call PQexec on a connection that is in the process of executing an SQL statement, you would cause a protocol violation. That just doesn't work.
Processing could certainly be made faster if you use several database connections in parallel — concurrent transactions is something that PostgreSQL is designed for.
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
If you try to call PQexec on a connection that is in the process of executing an SQL statement, you would cause a protocol violation. That just doesn't work.
Processing could certainly be made faster if you use several database connections in parallel — concurrent transactions is something that PostgreSQL is designed for.
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
answered Nov 15 '18 at 6:04
Laurenz AlbeLaurenz Albe
49k102848
49k102848
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
add a comment |
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Which means that if I give each thread 1 dbconnection, it should be fine for simultaneously insertion of results??
– Shore
Nov 15 '18 at 6:11
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
Yes, absolutely.
– Laurenz Albe
Nov 15 '18 at 6:12
add a comment |
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