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* Rethink heuristics for choosing index quals for parameterized paths.Tom Lane2012-09-16
| | | | | | | | | | | | | | | | | | | | | | Some experimentation with examples similar to bug #7539 has convinced me that indxpath.c's original implementation of parameterized-path generation was several bricks shy of a load. In general, if we are relying on a particular outer rel or set of outer rels for a parameterized path, the path should use every indexable join clause that's available from that rel or rels. Any join clauses that get left out of the indexqual will end up getting applied as plain filter quals (qpquals), and that's generally a significant loser compared to having the index AM enforce them. (This is particularly true with btree, which can skip the index scan entirely if it can see that the given indexquals are mutually contradictory.) The original heuristics failed to ensure this, though, and were overly complicated anyway. Rewrite to make the code explicitly identify each useful set of outer rels and then select all applicable join clauses for each one. The one plan that changes in the regression tests is in fact for the better according to the planner's cost estimates. (Note: this is not a correctness issue but just a matter of plan quality. I don't yet know what is going on in bug #7539, but I don't expect this change to fix that.)
* Fix bufmgr so CHECKPOINT_END_OF_RECOVERY behaves as a shutdown checkpoint.Simon Riggs2012-09-16
| | | | | | | | | Recovery code documents clearly that a shutdown checkpoint is executed at end of recovery - a shutdown checkpoint WAL record is written but the buffer manager had been altered to treat end of recovery as a normal checkpoint. This bug exacerbates the bufmgr relpersistence bug. Bug spotted by Andres Freund, patch by me.
* Properly set relpersistence for fake relcache entries.Robert Haas2012-09-14
| | | | | | | This can result in buffers failing to be properly flushed at checkpoint time, leading to data loss. Report, diagnosis, and patch by Jeff Davis.
* Fix case of window function + aggregate + GROUP BY expression.Tom Lane2012-09-13
| | | | | | | | | | | | | | | | In commit 1bc16a946008a7cbb33a9a06a7c6765a807d7f59 I added a minor optimization to drop the component variables of a GROUP BY expression from the target list computed at the aggregation level of a query, if those Vars weren't referenced elsewhere in the tlist. However, I overlooked that the window-function planning code would deconstruct such expressions and thus need to have access to their component variables. Fix it to not do that. While at it, I removed the distinction between volatile and nonvolatile window partition/order expressions: the code now computes all of them at the aggregation level. This saves a relatively expensive check for volatility, and it's unclear that the resulting plan isn't better anyway. Per bug #7535 from Louis-David Mitterrand. Back-patch to 9.2.
* Fix a couple other leftover uses of 'conisonly' terminology.Tom Lane2012-09-12
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* Fix logical errors in tsquery selectivity estimation for prefix queries.Tom Lane2012-09-11
| | | | | | | | | | | | | | | | | | | | | | I made multiple errors in commit 97532f7c29468010b87e40a04f8daa3eb097f654, stemming mostly from failure to think about the available frequency data as being element frequencies not value frequencies (so that occurrences of different elements are not mutually exclusive). This led to sillinesses such as estimating that "word" would match more rows than "word:*". The choice to clamp to a minimum estimate of DEFAULT_TS_MATCH_SEL also seems pretty ill-considered in hindsight, as it would frequently result in an estimate much larger than the available data suggests. We do need some sort of clamp, since a pattern not matching any of the MCELEMs probably still needs a selectivity estimate of more than zero. I chose instead to clamp to at least what a non-MCELEM word would be estimated as, preserving the property that "word:*" doesn't get an estimate less than plain "word", whether or not the word appears in MCELEM. Per investigation of a gripe from Bill Martin, though I suspect that his example case actually isn't even reaching the erroneous code. Back-patch to 9.1 where this code was introduced.
* Allow embedded spaces without quoting in unix_socket_directories entries.Tom Lane2012-09-06
| | | | | | | | | | | | | This fix removes an unnecessary incompatibility with the old behavior of the unix_socket_directory parameter. Since pathnames with embedded spaces are fairly popular on some platforms, the incompatibility could be significant in practice. We'll still strip unquoted leading/trailing spaces, however. No docs update since the documentation already implied that it worked like this. Per bug #7514 from Murray Cumming.
* Fix WAL file replacement during cascading replication on Windows.Heikki Linnakangas2012-09-05
| | | | | | | | | | | When the startup process restores a WAL file from the archive, it deletes any old file with the same name and renames the new file in its place. On Windows, however, when a file is deleted, it still lingers as long as a process holds a file handle open on it. With cascading replication, a walsender process can hold the old file open, so the rename() in the startup process would fail. To fix that, rename the old file to a temporary name, to make the original file name available for reuse, before deleting the old file.
* Fix inappropriate error messages for Hot Standby misconfiguration errors.Tom Lane2012-09-05
| | | | | | | | Give the correct name of the GUC parameter being complained of. Also, emit a more suitable SQLSTATE (INVALID_PARAMETER_VALUE, not the default INTERNAL_ERROR). Gurjeet Singh, errcode adjustment by me
* Fix PARAM_EXEC assignment mechanism to be safe in the presence of WITH.Tom Lane2012-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The planner previously assumed that parameter Vars having the same absolute query level, varno, and varattno could safely be assigned the same runtime PARAM_EXEC slot, even though they might be different Vars appearing in different subqueries. This was (probably) safe before the introduction of CTEs, but the lazy-evalution mechanism used for CTEs means that a CTE can be executed during execution of some other subquery, causing the lifespan of Params at the same syntactic nesting level as the CTE to overlap with use of the same slots inside the CTE. In 9.1 we created additional hazards by using the same parameter-assignment technology for nestloop inner scan parameters, but it was broken before that, as illustrated by the added regression test. To fix, restructure the planner's management of PlannerParamItems so that items having different semantic lifespans are kept rigorously separated. This will probably result in complex queries using more runtime PARAM_EXEC slots than before, but the slots are cheap enough that this hardly matters. Also, stop generating PlannerParamItems containing Params for subquery outputs: all we really need to do is reserve the PARAM_EXEC slot number, and that now only takes incrementing a counter. The planning code is simpler and probably faster than before, as well as being more correct. Per report from Vik Reykja. These changes will mostly also need to be made in the back branches, but I'm going to hold off on that until after 9.2.0 wraps.
* Trim spgist_private.h inclusionAlvaro Herrera2012-09-05
| | | | It doesn't really need rel.h; relcache.h is enough.
* Fix compiler warnings about unused variables, caused by my previous commit.Heikki Linnakangas2012-09-04
| | | | Reported by Peter Eisentraut.
* Fix bugs in cascading replication with recovery_target_timeline='latest'Heikki Linnakangas2012-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cascading replication code assumed that the current RecoveryTargetTLI never changes, but that's not true with recovery_target_timeline='latest'. The obvious upshot of that is that RecoveryTargetTLI in shared memory needs to be protected by a lock. A less obvious consequence is that when a cascading standby is connected, and the standby switches to a new target timeline after scanning the archive, it will continue to stream WAL to the cascading standby, but from a wrong file, ie. the file of the previous timeline. For example, if the standby is currently streaming from the middle of file 000000010000000000000005, and the timeline changes, the standby will continue to stream from that file. However, the WAL on the new timeline is in file 000000020000000000000005, so the standby sends garbage from 000000010000000000000005 to the cascading standby, instead of the correct WAL from file 000000020000000000000005. This also fixes a related bug where a partial WAL segment is restored from the archive and streamed to a cascading standby. The code assumed that when a WAL segment is copied from the archive, it can immediately be fully streamed to a cascading standby. However, if the segment is only partially filled, ie. has the right size, but only N first bytes contain valid WAL, that's not safe. That can happen if a partial WAL segment is manually copied to the archive, or if a partial WAL segment is archived because a server is started up on a new timeline within that segment. The cascading standby will get confused if the WAL it received is not valid, and will get stuck until it's restarted. This patch fixes that problem by not allowing WAL restored from the archive to be streamed to a cascading standby until it's been replayed, and thus validated.
* Fix serializable mode with index-only scans.Kevin Grittner2012-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | Serializable Snapshot Isolation used for serializable transactions depends on acquiring SIRead locks on all heap relation tuples which are used to generate the query result, so that a later delete or update of any of the tuples can flag a read-write conflict between transactions. This is normally handled in heapam.c, with tuple level locking. Since an index-only scan avoids heap access in many cases, building the result from the index tuple, the necessary predicate locks were not being acquired for all tuples in an index-only scan. To prevent problems with tuple IDs which are vacuumed and re-used while the transaction still matters, the xmin of the tuple is part of the tag for the tuple lock. Since xmin is not available to the index-only scan for result rows generated from the index tuples, it is not possible to acquire a tuple-level predicate lock in such cases, in spite of having the tid. If we went to the heap to get the xmin value, it would no longer be an index-only scan. Rather than prohibit index-only scans under serializable transaction isolation, we acquire an SIRead lock on the page containing the tuple, when it was not necessary to visit the heap for other reasons. Backpatch to 9.2. Kevin Grittner and Tom Lane
* Remove some useless trailing whitespaceMagnus Hagander2012-09-04
| | | | Michael Paquier
* Fix to_date() and to_timestamp() to allow specification of the day ofBruce Momjian2012-09-03
| | | | | | | the week via ISO or Gregorian designations. The fix is to store the day-of-week consistently as 1-7, Sunday = 1. Fixes bug reported by Marc Munro
* Replace memcpy() calls in xlog.c critical sections with struct assignments.Tom Lane2012-09-03
| | | | | | | | | | | | This gets rid of a dangerous-looking use of the not-volatile XLogCtl pointer in a couple of spinlock-protected sections, where the normal coding rule is that you should only access shared memory through a pointer-to-volatile. I think the risk is only hypothetical not actual, since for there to be a bug the compiler would have to move the spinlock acquire or release across the memcpy() call, which one sincerely hopes it will not. Still, it looks cleaner this way. Per comment from Daniel Farina and subsequent discussion.
* Drop cheap-startup-cost paths during add_path() if we don't need them.Tom Lane2012-09-01
| | | | | | | | | | | | | | | | | | We can detect whether the planner top level is going to care at all about cheap startup cost (it will only do so if query_planner's tuple_fraction argument is greater than zero). If it isn't, we might as well discard paths immediately whose only advantage over others is cheap startup cost. This turns out to get rid of quite a lot of paths in complex queries --- I saw planner runtime reduction of more than a third on one large query. Since add_path isn't currently passed the PlannerInfo "root", the easiest way to tell it whether to do this was to add a bool flag to RelOptInfo. That's a bit redundant, since all relations in a given query level will have the same setting. But in the future it's possible that we'd refine the control decision to work on a per-relation basis, so this seems like a good arrangement anyway. Per my suggestion of a few months ago.
* Fix mark_placeholder_maybe_needed to handle LATERAL references.Tom Lane2012-09-01
| | | | | | | | | | | | | | | If a PlaceHolderVar contains a pulled-up LATERAL reference, its minimum possible evaluation level might be higher in the join tree than its original syntactic location. That in turn affects the ph_needed level for any contained PlaceHolderVars (that is, those PHVs had better propagate up the join tree at least to the evaluation level of the outer PHV). We got this mostly right, but mark_placeholder_maybe_needed() failed to account for the effect, and in consequence could leave the inner PHVs with ph_may_need less than what their ultimate ph_needed value will be. That's bad because it could lead to failure to select a join order that will allow evaluation of the inner PHV at a valid location. Fix that, and add an Assert that checks that we don't ever set ph_needed to more than ph_may_need.
* Partially restore qual scope checks in distribute_qual_to_rels().Tom Lane2012-08-31
| | | | | | | | The LATERAL implementation is now basically complete, and I still don't see a cost-effective way to make an exact qual scope cross-check in the presence of LATERAL. However, I did add a PlannerInfo.hasLateralRTEs flag along the way, so it's easy to make the check only when not hasLateralRTEs. That seems to still be useful, and it beats having no check at all.
* Fix LATERAL references to join alias variables.Tom Lane2012-08-31
| | | | | I had thought this case worked already, but perhaps I didn't re-test it after adding extract_lateral_references() ...
* Make configure probe for mbstowcs_l as well as wcstombs_l.Tom Lane2012-08-31
| | | | | | | | | | | We previously supposed that any given platform would supply both or neither of these functions, so that one configure test would be sufficient. It now appears that at least on AIX this is not the case ... which is likely an AIX bug, but nonetheless we need to cope with it. So use separate tests. Per bug #6758; thanks to Andrew Hastie for doing the followup testing needed to confirm what was happening. Backpatch to 9.1, where we began using these functions.
* Fix typos in README.Heikki Linnakangas2012-08-31
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* Improve coding of gistchoose and gistRelocateBuildBuffersOnSplit.Tom Lane2012-08-30
| | | | | | | | This is mostly cosmetic, but it does eliminate a speculative portability issue. The previous coding ignored the fact that sum_grow could easily overflow (in fact, it could be summing multiple IEEE float infinities). On a platform where that didn't guarantee to produce a positive result, the code would misbehave. In any case, it was less than readable.
* Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera2012-08-30
| | | | | | | | | | | | This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
* Remove configure flag --disable-shared, as it is no longer used by anyBruce Momjian2012-08-30
| | | | port. The last use was QNX, per Peter Eisentraut.
* Suppress creation of backwardly-indexed paths for LATERAL join clauses.Tom Lane2012-08-30
| | | | | | | | | | | | | Given a query such as SELECT * FROM foo JOIN LATERAL (SELECT foo.var1) ss(x) ON ss.x = foo.var2 the existence of the join clause "ss.x = foo.var2" encourages indxpath.c to build a parameterized path for foo using any index available for foo.var2. This is completely useless activity, though, since foo has got to be on the outside not the inside of any nestloop join with ss. It's reasonably inexpensive to add tests that prevent creation of such paths, so let's do that.
* Fix division by zero in the new range type histogram creation.Heikki Linnakangas2012-08-30
| | | | Report and analysis by Matthias.
* Add missing period to detail message.Robert Haas2012-08-30
| | | | Per note from Peter Eisentraut.
* Fix logic bug in gistchoose and gistRelocateBuildBuffersOnSplit.Robert Haas2012-08-30
| | | | | | | | | | | | Every time the best-tuple-found-so-far changes, we need to reset all the penalty values in which_grow[] to the penalties for the new best tuple. The old code failed to do this, resulting in inferior index quality. The original patch from Alexander Korotkov was just two lines; I took the liberty of fleshing that out by adding a bunch of comments that I hope will make this logic easier for others to understand than it was for me.
* Improve EXPLAIN's ability to cope with LATERAL references in plans.Tom Lane2012-08-30
| | | | | | | | | | push_child_plan/pop_child_plan didn't bother to adjust the "ancestors" list of parent plan nodes when descending to a child plan node. I think this was okay when it was written, but it's not okay in the presence of LATERAL references, since a subplan node could easily be returning a LATERAL value back up to the same nestloop node that provides the value. Per changed regression test results, the omission led to failure to interpret Param nodes that have perfectly good interpretations.
* Comment fixes.Robert Haas2012-08-30
| | | | Jeff Davis, somewhat edited by me
* Adjust definition of cheapest_total_path to work better with LATERAL.Tom Lane2012-08-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the initial cut at LATERAL, I kept the rule that cheapest_total_path was always unparameterized, which meant it had to be NULL if the relation has no unparameterized paths. It turns out to work much more nicely if we always have *some* path nominated as cheapest-total for each relation. In particular, let's still say it's the cheapest unparameterized path if there is one; if not, take the cheapest-total-cost path among those of the minimum available parameterization. (The first rule is actually a special case of the second.) This allows reversion of some temporary lobotomizations I'd put in place. In particular, the planner can now consider hash and merge joins for joins below a parameter-supplying nestloop, even if there aren't any unparameterized paths available. This should bring planning of LATERAL-containing queries to the same level as queries not using that feature. Along the way, simplify management of parameterized paths in add_path() and friends. In the original coding for parameterized paths in 9.2, I tried to minimize the logic changes in add_path(), so it just treated parameterization as yet another dimension of comparison for paths. We later made it ignore pathkeys (sort ordering) of parameterized paths, on the grounds that ordering isn't a useful property for the path on the inside of a nestloop, so we might as well get rid of useless parameterized paths as quickly as possible. But we didn't take that reasoning as far as we should have. Startup cost isn't a useful property inside a nestloop either, so add_path() ought to discount startup cost of parameterized paths as well. Having done that, the secondary sorting I'd implemented (in add_parameterized_path) is no longer needed --- any parameterized path that survives add_path() at all is worth considering at higher levels. So this should be a bit faster as well as simpler.
* Report postmaster.pid file as empty if it is empty, rather thanBruce Momjian2012-08-29
| | | | reporting in contains invalid data.
* Optimize SP-GiST insertions.Heikki Linnakangas2012-08-29
| | | | | | | This includes two micro-optimizations to the tight inner loop in descending the SP-GiST tree: 1. avoid an extra function call to index_getprocinfo when calling user-defined choose function, and 2. avoid a useless palloc+pfree when node labels are not used.
* Split heapam_xlog.h from heapam.hAlvaro Herrera2012-08-28
| | | | | | | | | | | | The heapam XLog functions are used by other modules, not all of which are interested in the rest of the heapam API. With this, we let them get just the XLog stuff in which they are interested and not pollute them with unrelated includes. Also, since heapam.h no longer requires xlog.h, many files that do include heapam.h no longer get xlog.h automatically, including a few headers. This is useful because heapam.h is getting pulled in by execnodes.h, which is in turn included by a lot of files.
* remove catcache.h from syscache.hAlvaro Herrera2012-08-28
| | | | | Instead, place a forward struct declaration for struct catclist in syscache.h. This reduces header proliferation somewhat.
* Split resowner.hAlvaro Herrera2012-08-28
| | | | | This lets files that are mere users of ResourceOwner not automatically include the headers for stuff that is managed by the resowner mechanism.
* Fix DROP INDEX CONCURRENTLY IF EXISTS.Tom Lane2012-08-27
| | | | | | | | This threw ERROR, not the expected NOTICE, if the index didn't exist. The bug was actually visible in not-as-expected regression test output, so somebody wasn't paying too close attention in commit 8cb53654dbdb4c386369eb988062d0bbb6de725e. Per report from Brendan Byrd.
* Collect and use histograms of lower and upper bounds for range types.Heikki Linnakangas2012-08-27
| | | | | | | | | | | | | | | This enables selectivity estimation of the <<, >>, &<, &> and && operators, as well as the normal inequality operators: <, <=, >=, >. "range @> element" is also supported, but the range-variant @> and <@ operators are not, because they cannot be sensibly estimated with lower and upper bound histograms alone. We would need to make some assumption about the lengths of the ranges for that. Alexander's patch included a separate histogram of lengths for that, but I left that out of the patch for simplicity. Hopefully that will be added as a followup patch. The fraction of empty ranges is also calculated and used in estimation. Alexander Korotkov, heavily modified by me.
* Fix up planner infrastructure to support LATERAL properly.Tom Lane2012-08-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch takes care of a number of problems having to do with failure to choose valid join orders and incorrect handling of lateral references pulled up from subqueries. Notable changes: * Add a LateralJoinInfo data structure similar to SpecialJoinInfo, to represent join ordering constraints created by lateral references. (I first considered extending the SpecialJoinInfo structure, but the semantics are different enough that a separate data structure seems better.) Extend join_is_legal() and related functions to prevent trying to form unworkable joins, and to ensure that we will consider joins that satisfy lateral references even if the joins would be clauseless. * Fill in the infrastructure needed for the last few types of relation scan paths to support parameterization. We'd have wanted this eventually anyway, but it is necessary now because a relation that gets pulled up out of a UNION ALL subquery may acquire a reltargetlist containing lateral references, meaning that its paths *have* to be parameterized whether or not we have any code that can push join quals down into the scan. * Compute data about lateral references early in query_planner(), and save in RelOptInfo nodes, to avoid repetitive calculations later. * Assorted corner-case bug fixes. There's probably still some bugs left, but this is a lot closer to being real than it was before.
* Allow text timezone designations, e.g. "America/Chicago", when using theBruce Momjian2012-08-25
| | | | ISO "T" timestamptz format.
* Fix issues with checks for unsupported transaction states in Hot Standby.Tom Lane2012-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | The GUC check hooks for transaction_read_only and transaction_isolation tried to check RecoveryInProgress(), so as to disallow setting read/write mode or serializable isolation level (respectively) in hot standby sessions. However, GUC check hooks can be called in many situations where we're not connected to shared memory at all, resulting in a crash in RecoveryInProgress(). Among other cases, this results in EXEC_BACKEND builds crashing during child process start if default_transaction_isolation is serializable, as reported by Heikki Linnakangas. Protect those calls by silently allowing any setting when not inside a transaction; which is okay anyway since these GUCs are always reset at start of transaction. Also, add a check to GetSerializableTransactionSnapshot() to complain if we are in hot standby. We need that check despite the one in check_XactIsoLevel() because default_transaction_isolation could be serializable. We don't want to complain any sooner than this in such cases, since that would prevent running transactions at all in such a state; but a transaction can be run, if SET TRANSACTION ISOLATION is done before setting a snapshot. Per report some months ago from Robert Haas. Back-patch to 9.1, since these problems were introduced by the SSI patch. Kevin Grittner and Tom Lane, with ideas from Heikki Linnakangas
* Fix cascading privilege revoke to notice when privileges are still held.Tom Lane2012-08-23
| | | | | | | | | | | | If we revoke a grant option from some role X, but X still holds the option via another grant, we should not recursively revoke the privilege from role(s) Y that X had granted it to. This was supposedly fixed as one aspect of commit 4b2dafcc0b1a579ef5daaa2728223006d1ff98e9, but I must not have tested it, because in fact that code never worked: it forgot to shift the grant-option bits back over when masking the bits being revoked. Per bug #6728 from Daniel German. Back-patch to all active branches, since this has been wrong since 8.0.
* Avoid somewhat-theoretical overflow risks in RecordIsValid().Tom Lane2012-08-21
| | | | | | | | | | | | | This improves on commit 51fed14d73ed3acd2282b531fb1396877e44e86a by eliminating the assumption that we can form <some pointer value> + <some offset> without overflow. The entire point of those tests is that we don't trust the offset value, so coding them in a way that could wrap around if the buffer happens to be near the top of memory doesn't seem sound. Instead, track the remaining space as a size_t variable and compare offsets against that. Also, improve comment about why we need the extra early check on xl_tot_len.
* Improve C comments in GetSnapshotData.Robert Haas2012-08-21
| | | | | | Move discussion of why our algorithm for taking snapshots in recovery to a more appropriate location in the function, and delete incorrect mention of taking a lock.
* Remove external PID file on postmaster exitPeter Eisentraut2012-08-20
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* Don't get confused if a WAL partial record header has xl_tot_len == 0.Heikki Linnakangas2012-08-20
| | | | | | | | | | | | | | | If a WAL record header was split across pages, but xl_tot_len was 0, we would get confused and conclude that we had already read the whole record, and proceed to CRC check it. That can lead to a crash in RecordIsValid(), which isn't careful to not read beyond end-of-record, as defined by xl_tot_len. Add an explicit sanity check for xl_tot_len <= SizeOfXlogRecord. Also, make RecordIsValid() more robust by checking in each step that it doesn't try to access memory beyond end of record, even if a length field in the record's or a backup block's header is bogus. Per report and analysis by Tom Lane.
* Remove obsolete comment.Tom Lane2012-08-19
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* Allow OLD and NEW in multi-row VALUES within rules.Tom Lane2012-08-19
| | | | | Now that we have LATERAL, it's fairly painless to allow this case, which was left as a TODO in the original multi-row VALUES implementation.