On 4/3/2024 09:26, jian he wrote:
On Thu, Feb 29, 2024 at 4:59 PM Andrei Lepikhov
Feel free to add, change or totally rewrite these changes.
On replacement of static ScalarArrayOpExpr dest with dynamic allocated one:
After discussion [1] I agree with that replacement.
Some style (and language) changes in comments I haven't applied because
it looks debatable for me.
I think it should be something like:
+ gettext_noop("Transform a sequence of OR expressions to an array
expression."),
+ gettext_noop("The planner will replace expression like 'x=c1 OR x=c2 "
+ "to the expression 'x = ANY( ARRAY[c1,c2])''"
Fixed
queryId may not be a good variable name here?
Not sure. QueryId is a concept, part of queryjumble technique and can be
used by other tools. It just tells the developer what it is the same
thing as Query Jumbling but for a separate expression.
At least you don't insist on removing of JumbleState return pointer that
looks strange for a simple hash ...
comment `/* Compute query ID */`
seems not correct, here we are just hashing the expression?
The same as above.
+/*
+ * Dynahash match function to use in guc_hashtab
the above comments seem not correct?
Yes, fixed.
` It applies to equality expressions only.` seems not correct?
`select * from tenk1 where unique1 < 1 or unique1 < 2; ` can also do
the transformation.
Yes, I forgot it.
`similarity of variable sides.` seems not correct,
should it be 'sameness of the variable sides`?
The term 'equivalence' looks better *).
in [2], we can get:
SOME is a synonym for ANY. IN is equivalent to = ANY.
but still transforming OR to ANY is not intuitive.
a normal user may not know what is "transforming OR to ANY".
so maybe adding a simple example at
<varlistentry id="guc-enable-or-transformation"
xreflabel="enable_or_transformation">
would be great. which, I did at previous thread.
Not sure. Examples in that section are unusual things. What's more,
should a user who doesn't know what it means to change this setting?
Let's wait for other opinions.
[1] https://www.postgresql.org/message-id/2157387.1709068...@sss.pgh.pa.us
--
regards,
Andrei Lepikhov
Postgres Professional
