Hi Sanjay, > On 19 Apr 2021, at 18:14, Sanjay Minni <s...@planage.com> wrote: > > Hi > > using the P3 Postgres driver > > what is the optimised way of using the following in a seaside/web > application > statement := client prepare: ... > statement execute: > statement close. > > Sven readme on the drivers page > "prepared statements ... need to be closed, prepared statement exist ... > single session / connection ..."
First make sure that you give each session in your (seaside) web application its own connection/client to the database. P3Client is meant to be used single threaded, it is your responsibility to protect this. Make sure these are initialised and disposed of properly - use logging. Second, I would not put time in trying to gain performance with prepared statements until you can prove that it makes a real, measurable difference. PostgreSQL is very fast. But this is IMHO. See further. > Typically in a desktop app I would fire the "prepare" statements(s) once > when open the particular UI / window (say typically 2 or 3 statements in a > UI) and then "close" when I exit > > How does this work in a multi-tabbed browser app > lets say I open a tab with a particular UI and fire the "prepare" statement > > now what if the tab idles for too long - and then i press send/save. The > program would have just fired the "execute ..." assuming the prepare is > active. would the prepare / session have been automatically closed ? > > - when should i typically fire the prepare statement Either upfront when you connect, or each time when you need them (see further). The scope of a prepared statement is the connection/session. Preparing 10s of statements upfront that you might not need could increase connection time. > - how should i test if the session / prepare is still active or needs to be > refired There is P3Client>>#preparedStatementNamed: You best use P3Client>>#prepare:named: then. > - how are orphan prepare statements disposed off ny the database / program They get thrown out when the connection closes. HTH, Sven PS: There is also P3ConnectionPool that can protect against concurrent access, prepare connections, warm up, on top of its base functionality of pooling, of course. But a challenge with connection pooling is what to do when errors occur. > thanks for pointers > Sanjay > > > > ----- > cheers, > Sanjay > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
