Postgres Pro
Downloads
Home   >   mailing lists

Thread: Fwd: postgres join query.

Fwd: postgres join query.

From
Rahul Ranjan
Date:
Hi,

I am using join query as below.

java code
=================
sqlQuery="insert into locations_graphic_map_ksk(chain, screen,template,location,language,graphic_up_filename,graphic_up,graphic_up_descr,graphic_dn_filename,graphic_dn,graphic_dn_descr)"
                              + " select t1.chain, t1.screen, t1.template, t1.location, t1.language, t1.graphic_up_filename, t2.graphic, t2.graphic_descr, t1.graphic_dn_filename, t3.graphic, t3.graphic_descr "
                              + "from locations_graphic_map_ksk_tmp as t1, loc_graphic_map_ksk_up as t2, loc_graphic_map_ksk_dn as t3 where t1.graphic_up_filename=t2.graphic_filename and t1.graphic_dn_filename=t3.graphic_filename";
 
st=conn.createStatement();
 st.executeUpdate(sqlQuery);


I have one doubt that, are  all results get loaded to main memory from join then it does insertion
or it retrieves few records and do insertion and so on?

Please help.

Thanks,
rahul

Re: Fwd: postgres join query.

From
Dave Cramer
Date:
Rahul,

This really isn't a JDBC question, but the answer is this executes totally on the server. It does not load anything into the JDBC memory context, it may or may not load everything into the servers memory depending on the size of the select

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca


On Tue, Nov 19, 2013 at 4:10 AM, Rahul Ranjan <rahul.sdabahar@gmail.com> wrote:
Hi,

I am using join query as below.

java code
=================
sqlQuery="insert into locations_graphic_map_ksk(chain, screen,template,location,language,graphic_up_filename,graphic_up,graphic_up_descr,graphic_dn_filename,graphic_dn,graphic_dn_descr)"
                              + " select t1.chain, t1.screen, t1.template, t1.location, t1.language, t1.graphic_up_filename, t2.graphic, t2.graphic_descr, t1.graphic_dn_filename, t3.graphic, t3.graphic_descr "
                              + "from locations_graphic_map_ksk_tmp as t1, loc_graphic_map_ksk_up as t2, loc_graphic_map_ksk_dn as t3 where t1.graphic_up_filename=t2.graphic_filename and t1.graphic_dn_filename=t3.graphic_filename";
 
st=conn.createStatement();
 st.executeUpdate(sqlQuery);


I have one doubt that, are  all results get loaded to main memory from join then it does insertion
or it retrieves few records and do insertion and so on?

Please help.

Thanks,
rahul