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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Chao Li <li.evan.chao@gmail.com>
cc: pgsql-hackers@lists.postgresql.org
Subject: Re: Residual tsquery cleanups
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Comments: In-reply-to Chao Li <li.evan.chao@gmail.com>
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Chao Li <li.evan.chao@gmail.com> writes:
> Overall looks good to me. A few small comments:

> 1 - 0001
> ```
> +				unsigned int dist =3D pq_getmsgint(buf, sizeof(int16));
> +
> +				if (dist > MAXENTRYPOS)
> +					elog(ERROR, "invalid tsquery: invalid phrase distance %d",
> +						 dist);
> ```

> Here, =E2=80=9Cdist=E2=80=9D is an unsigned int, so maybe it would be be=
tter to use =E2=80=9C%u=E2=80=9D than =E2=80=9C%d=E2=80=9D to print it.

Hmm ... doesn't really matter, since pq_getmsgint's result is
guaranteed to be in 0..65535.  But OK.

> 2 - 0002
> =C2=B7=C2=B7=C2=B7
> +     <para>The length of a <type>tsquery</type>'s data (lexemes only)
> +     must be less than 1 megabyte</para>
> =C2=B7=C2=B7=C2=B7

> Look like to me this is inaccurate, because in pushValue_internal(), the=
 "if (distance > MAXSTRPOS)=E2=80=9D check happens before adding a new ele=
ment, thus distance may exceed MAXSTRPOS after the element is added.

True, it can be up to one lexeme more.  But I didn't think it was
worth trying to go into that much detail.  As a comparison point,
the corresponding bullet for tsvector doesn't explain how to calculate
the space used for lexeme positions.  I think the main takeaway here
is just that there *is* a limit of this type.  People who really want
to know the exact details can consult the source code.

			regards, tom lane