to avoid undue sensitivity to roundoff error, believe that a zero
or slightly negative range estimate should represent a small
positive selectivity, rather than falling back on a generic default
estimate.
use a default value that's fairly small. We were generating a result
of about 0.1, but I think 0.01 is probably better --- want to encourage
use of an indexscan in this situation.
costs using the inner path's parent->rows count as the number of tuples
processed per inner scan iteration. This is wrong when we are using an
inner indexscan with indexquals based on join clauses, because the rows
count in a Relation node reflects the selectivity of the restriction
clauses for that rel only. Upshot was that if join clause was very
selective, we'd drastically overestimate the true cost of the join.
Fix is to calculate correct output-rows estimate for an inner indexscan
when the IndexPath node is created and save it in the path node.
Change of path node doesn't require initdb, since path nodes don't
appear in saved rules.
to simplify constant expressions and expand SubLink nodes into SubPlans
is done in a separate routine subquery_planner() that calls union_planner().
We formerly did most of this work in query_planner(), but that's the
wrong place because it may never see the real targetlist. Splitting
union_planner into two routines also allows us to avoid redundant work
when union_planner is invoked recursively for UNION and inheritance
cases. Upshot is that it is now possible to do something like
select float8(count(*)) / (select count(*) from int4_tbl) from int4_tbl
group by f1;
which has never worked before.
had already been transformed. This led to failure in examples like
UPDATE table SET fld = (SELECT ...). Repair this, and revise the
comments to explain that transformExpr has to be robust against this
condition. Someday we might want to fix the callers so that
transformExpr is never invoked on its own output, but that someday
is not today.
In function parsing, try for an actual function of the given name and
input types before trying to interpret the function call as a type
coercion request, rather than after. Before, a function that had the
same name as a type and operated on a binary-compatible type wouldn't
get invoked. Also, cross-pollinate between func_select_candidates and
oper_select_candidates to ensure that they use as nearly the same
resolution rules as possible. A few other minor code cleanups too.
problem could be lack of parentheses. This addresses cases like
X UserOp UserOp Y, which will be parsed as (X UserOp) UserOp Y,
whereas what likely was wanted was X UserOp (UserOp Y).
16-Mar-00: trailing + or - is not part of the operator unless the operator
also contains characters not present in SQL92-defined operators. This
solves the 'X=-Y' problem without unduly constraining users' choice of
operator names --- in particular, no existing Postgres operator names
become invalid.
Also, remove processing of // comments, as agreed in the same thread.
running gcc and HP's cc with warnings cranked way up. Signed vs unsigned
comparisons, routines declared static and then defined not-static,
that kind of thing. Tedious, but perhaps useful...
actually a type-coercion problem. If you have a function defined on
class A, and class B inherits from A, then the function ought to work
on class B as well --- but coerce_type didn't know that. Now it does.
mark query as having subselects if a subselect was added from a rule
WHERE condition (as opposed to a rule action). Also, fix adjustment
of varlevelsup so that it actually has some prospect of working when
inserting an expression containing a subselect into a subquery.
small changes in formatting.c code (better memory usage ...etc.) and
better
to_char's cache (will fastly for more to_char()s in one query).
(It is probably end of to_char() development in 7.0 cycle.)
Karel
after trying to resolve the item as an input-column name. This allows us
to be compliant with the SQL92 spec for queries that fall within the spec,
while still accepting the same out-of-spec queries as 6.5 did. You'll only
lose if there is an output column name that is the same as an input
column name, but doesn't refer to the same value. 7.0 will interpret
such a GROUP BY spec differently than 6.5 did. No way around that, because
6.5 was clearly not spec compliant.
CREATE DB/DROP DB. If you didn't think they were wrong, try what
happens when you compile with -DCLOBBER_FREED_MEMORY --- database
name displayed in error messages is trashed, because transaction
abort freed it. Also, remove trailing periods in error messages,
per our prevailing style.
Implement TIME WITH TIME ZONE type (timetz internal type).
Remap length() for character strings to CHAR_LENGTH() for SQL92
and to remove the ambiguity with geometric length() functions.
Keep length() for character strings for backward compatibility.
Shrink stored views by removing internal column name list from visible rte.
Implement min(), max() for time and timetz data types.
Implement conversion of TIME to INTERVAL.
Implement abs(), mod(), fac() for the int8 data type.
Rename some math functions to generic names:
round(), sqrt(), cbrt(), pow(), etc.
Rename NUMERIC power() function to pow().
Fix int2 factorial to calculate result in int4.
Enhance the Oracle compatibility function translate() to work with string
arguments (from Edwin Ramirez).
Modify pg_proc system table to remove OID holes.
(ie, allow rounding to occur at a digit position left of the decimal
point). Apparently this is how Oracle handles it, and there are
precedents in other programming languages as well.
Since we detect oversize tuples elsewhere, I see no reason not to allow
string constants that are 'too long' --- after all, they might never get
stored in a tuple at all.
YY_READ_BUF_SIZE, which turns out to have nothing to do with buffer size.
It's just a totally arbitrary upper limit on how much data myinput() is
asked for at one time.
