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Thread: when construct new tuple for update?

when construct new tuple for update?

From
mohsen soodkhah mohammadi
Date:
hi
I want that find where did a new tuple data construct in postgresql code when query is update.
I find that ExecModiryTable is an upper function for do it. but I want to find exact place that create the data of one row of table.
can you help me?

Re: when construct new tuple for update?

From
Amit Kapila
Date:
On Wed, Sep 18, 2013 at 2:21 PM, mohsen soodkhah mohammadi
<mohsensoodkhah@gmail.com> wrote:
> hi
> I want that find where did a new tuple data construct in postgresql code
> when query is update.
> I find that ExecModiryTable is an upper function for do it. but I want to
> find exact place that create the data of one row of table.

heap_form_tuple() construct a new tuple from the given values[] and
isnull[] arrays and incase of UPDATE operation, it gets called in
below call stack
ExecModifyTable()->ExecUpdate()->ExecMaterializeSlot()->ExecCopySlotTuple()->heap_form_tuple()

Values to construct new tuple are formed during projection in
ExecProject() which is called as below call stack in UPDATE operation:
ExecModifyTable()->ExecProcNode()->ExecSeqScan()->ExecScan()->ExecProject()


With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com