Re: [HACKERS] Changes in Trigger Firing
I read somewhere that the best editor is the one you master (1) :) 1: http://www.postgresql.org/message-id/m2wrs6giyp@hi-media.com Thanks, I am using eclipse now. Any comments about the utility of this feature? Or is it just me who thinks this can be useful? I think users/developers of trigger based replication tools can benefit from this. I am not sure how replication tools like slony handle a scenario where replicated table is partitioned and I add a new partition to it. Regards Sameer
Re: [HACKERS] Changes in Trigger Firing
I have been finally able to get the right set of files. I going with below approach: 1) Add a new column in pg_trigger called tgiscascaded 2) Change pg_trigger.h for this 3) Made changes in trigger.c to insert this values 4) Corresponding changes made in - reltrigger.h - parsenode.h 5) Changed gram.y to understand a new key word in CREATE TRIGGER statement CASCADED. - The new option will be optional and will apply only to non-constraint triggers - If the option is specified trigger will CASCADE to child tables 6) I just complied the source code (modified with above changes) and it - Added a new column in pg_trigger - The new column is able to derive its value from CREATE TRIGGER statement based on whether CASDADED was specified or not - The value is True if the option was specified - The value is false if the option was not specified 7) Now I will work on trigger firing mechanism with below approach - Before firing triggers, check if it's an inherited table - First get CASCADED triggers for parents and fire them - Proceed as usual Any suggestion on improving the approach or comments on need for this feature are welcome. Regards Sameer
Re: [HACKERS] Changes in Trigger Firing
One scenario where I can forsee an issue is when someone uses the tablename with-in the trigger function on which the trigger was fired. I am not sure how and what issue might crop up but this will be one of my test cases. -- View this message in context: http://postgresql.1045698.n5.nabble.com/Hacker-RFC-Changes-in-Trigger-Firing-tp5781566p5781861.html Sent from the PostgreSQL - hackers mailing list archive at Nabble.com. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Changes in Trigger Firing
Sameer Kumar wrote: CreateTrigStmt is passed to CreateTrigger function as an arguement. I am struggling to understand how the values for various members of trigger are set and where [which file] calls CreateTrigStmt. Can someone provide some help on this? I think you need better tools to guide you in exploring the source code. For example, you can use cscope to tell you where is CreateTrigStmt used, and you would find gram.y; and use it to tell you where CreateTrigger is used, and you would find utility.c. Any half-decent code editor should be able to generate a database of symbols and let you frolic around the various files quickly. Without that, anyone would be completely lost in developing new features of even the lowest complexity. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Changes in Trigger Firing
CreateTrigStmt is passed to CreateTrigger function as an arguement. I am struggling to understand how the values for various members of trigger are set and where [which file] calls CreateTrigStmt. Can someone provide some help on this? I think you need better tools to guide you in exploring the source code. For example, you can use cscope to tell you where is CreateTrigStmt used, and you would find gram.y; and use it to tell you where CreateTrigger is used, and you would find utility.c. Thanks for your advice. I was relying on PostgreSQL documentation which was quite helpful so far. Let me try some development tool. Any half-decent code editor should be able to generate a database of symbols and let you frolic around the various files quickly. Without that, anyone would be completely lost in developing new features of even the lowest complexity. Got the point!
Re: [HACKERS] Changes in Trigger Firing
On Wed, Dec 4, 2013 at 11:16 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: Sameer Kumar wrote: I think you need better tools to guide you in exploring the source code. For example, you can use cscope to tell you where is CreateTrigStmt used, and you would find gram.y; and use it to tell you where CreateTrigger is used, and you would find utility.c. Any half-decent code editor should be able to generate a database of symbols and let you frolic around the various files quickly. Without that, anyone would be completely lost in developing new features of even the lowest complexity. Not always, other people find as well git grep quite useful when coding a complex tree. I read somewhere that the best editor is the one you master (1) :) 1: http://www.postgresql.org/message-id/m2wrs6giyp@hi-media.com -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Changes in Trigger Firing
Hi all, I am doing some changes in trigger firing mechanism (as a POC first, I will share my work if people find it useful and if it works). I am going to extend the trigger calls to child tables. So that in trigger definition I can create triggers with CASCADED TRUE | FALSE option. This will enable me to extend certain triggers to child tables and get over the scenarios when a record gets inserted in child table and any *after insert* triggers on parent tables never get fired. I am right now trying to change pg_trigger and CreateTrigger function. I have made changes in below files: trigger.c: - Added a New Variable cascadedOption (bool) - Added a new statement in trigger.c to set the value: values[Anum_pg_trigger_tgiscascaded - 1] = BoolGetDatum(stmt-cascadedOption); - Added a new column in CATALOG definition of pg_trigger in pg_trigger.h bool tgiscascaded; - In pg_trigger.h, added a new position for values #define Anum_pg_trigger_tgiscascaded16 - Modified parsenode.h to add a new element in Structure for trigger statement -CreateTrigStmt boolcascadedOption; CreateTrigStmt is passed to CreateTrigger function as an arguement. I am struggling to understand how the values for various members of trigger are set and where [which file] calls CreateTrigStmt. Can someone provide some help on this? Best Regards, *Sameer Kumar | Database Consultant* *ASHNIK PTE. LTD. *101 Cecil Street, #11-11 Tong Eng Building, Singapore 069533 M : *+65 8110 0350* T: +65 6438 3504 | www.ashnik.com www.facebook.com/ashnikbiz | www.twitter.com/ashnikbiz [image: email patch] This email may contain confidential, privileged or copyright material and is solely for the use of the intended recipient(s). image002.jpg
