Up to now, we sent a ParameterStatus message to the client immediately
upon any change in the active value of any GUC_REPORT variable. This
was only barely okay when the feature was designed; now that we have
things like function SET clauses, there are very plausible use-cases
where a GUC_REPORT variable might change many times within a query
--- and even end up back at its original value, perhaps. Fortunately
most of our GUC_REPORT variables are unlikely to be changed often;
but there are proposals in play to enlarge that set, or even make it
user-configurable.
Hence, let's fix things to not generate more than one ParameterStatus
message per variable per query, and to not send any message at all
unless the end-of-query value is different from what we last reported.
Discussion: https://postgr.es/m/5708.1601145259@sss.pgh.pa.us
The BKI file's string quoting conventions were previously quite weird,
perhaps as a result of repurposing a function built to scan
single-quoted strings to scan double-quoted ones. Change to use the
same rules as we use in GUC files, allowing some simplifications in
genbki.pl and initdb.c.
While at it, completely remove the backend's scanstr() function, which
was essentially a duplicate of the string dequoting code in guc-file.l.
Instead export that one (under a less generic name than it had) and let
bootscanner.l use it. Now we can clarify that scansup.c exists only to
support the main lexer. We could alternatively have removed GUC_scanstr,
but this way seems better since the previous arrangement could mislead
a reader into thinking that scanstr() had something to do with the main
lexer's handling of string literals. Maybe it did once, but if so it
was a long time ago.
This patch does not bump catversion, since the initially-installed
catalog contents don't change. Note however that successful initdb
after applying this patch will require up-to-date postgres.bki as well
as postgres and initdb executables.
In passing, remove a bunch of very-long-obsolete #include's in
bootparse.y and bootscanner.l.
John Naylor
Discussion: https://postgr.es/m/CACPNZCtDpd18T0KATTmCggO2GdVC4ow86ypiq5ENff1VnauL8g@mail.gmail.com
This patch replaces the boolean GUC log_parameters_on_error introduced
by commit ba79cb5dc with an integer log_parameter_max_length_on_error,
adding the ability to specify how many bytes to trim each logged
parameter value to. (The previous coding hard-wired that choice at
64 bytes.)
In addition, add a new parameter log_parameter_max_length that provides
similar control over truncation of query parameters that are logged in
response to statement-logging options, as opposed to errors. Previous
releases always logged such parameters in full, possibly causing log
bloat.
For backwards compatibility with prior releases,
log_parameter_max_length defaults to -1 (log in full), while
log_parameter_max_length_on_error defaults to 0 (no logging).
Per discussion, log_parameter_max_length is SUSET since the DBA should
control routine logging behavior, but log_parameter_max_length_on_error
is USERSET because it also affects errcontext data sent back to the
client.
Alexey Bashtanov, editorialized a little by me
Discussion: https://postgr.es/m/b10493cc-a399-a03a-67c7-068f2791ee50@imap.cc
This makes such log entries more useful, since the cause of the error
can be dependent on the parameter values.
Author: Alexey Bashtanov, Álvaro Herrera
Discussion: https://postgr.es/m/0146a67b-a22a-0519-9082-bc29756b93a2@imap.cc
Reviewed-by: Peter Eisentraut, Andres Freund, Tom Lane
Add some support for automatically showing backtraces in certain error
situations in the server. Backtraces are shown on assertion failure;
also, a new setting backtrace_functions can be set to a list of C
function names, and all ereport()s and elog()s from the mentioned
functions will have backtraces generated. Finally, the function
errbacktrace() can be manually added to an ereport() call to generate a
backtrace for that call.
Authors: Peter Eisentraut, Álvaro Herrera
Discussion: https://postgr.es/m//5f48cb47-bf1e-05b6-7aae-3bf2cd01586d@2ndquadrant.com
Discussion: https://postgr.es/m/CAMsr+YGL+yfWE=JvbUbnpWtrRZNey7hJ07+zT4bYJdVp4Szdrg@mail.gmail.com
This allows logging a sample of statements, without incurring excessive
log traffic (which may impact performance). This can be useful when
analyzing workloads with lots of short queries.
The sampling is configured using two new GUC parameters:
* log_min_duration_sample - minimum required statement duration
* log_statement_sample_rate - sample rate (0.0 - 1.0)
Only statements with duration exceeding log_min_duration_sample are
considered for sampling. To enable sampling, both those GUCs have to
be set correctly.
The existing log_min_duration_statement GUC has a higher priority, i.e.
statements with duration exceeding log_min_duration_statement will be
always logged, irrespectedly of how the sampling is configured. This
means only configurations
log_min_duration_sample < log_min_duration_statement
do actually sample the statements, instead of logging everything.
Author: Adrien Nayrat
Reviewed-by: David Rowley, Vik Fearing, Tomas Vondra
Discussion: https://postgr.es/m/bbe0a1a8-a8f7-3be2-155a-888e661cc06c@anayrat.info
This reverts commit 88bdbd3f74.
As committed, statement sampling used the existing duration threshold
(log_min_duration_statement) when decide which statements to sample.
The issue is that even the longest statements are subject to sampling,
and so may not end up logged. An improvement was proposed, introducing
a second duration threshold, but it would not be backwards compatible.
So we've decided to revert this feature - the separate threshold should
be part of the feature itself.
Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com
These were introduced by pgindent due to fixe to broken
indentation (c.f. 8255c7a5ee). Previously the mis-indentation of
function prototypes was creatively used to reduce indentation in a few
places.
As that formatting only exists in master and REL_12_STABLE, it seems
better to fix it in both, rather than having some odd indentation in
v12 that somebody might copy for future patches or such.
Author: Andres Freund
Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de
Backpatch: 12-
Similarly to the set of parameters for keepalive, a connection parameter
for libpq is added as well as a backend GUC, called tcp_user_timeout.
Increasing the TCP user timeout is useful to allow a connection to
survive extended periods without end-to-end connection, and decreasing
it allows application to fail faster. By default, the parameter is 0,
which makes the connection use the system default, and follows a logic
close to the keepalive parameters in its handling. When connecting
through a Unix-socket domain, the parameters have no effect.
Author: Ryohei Nagaura
Reviewed-by: Fabien Coelho, Robert Haas, Kyotaro Horiguchi, Kirk
Jamison, Mikalai Keida, Takayuki Tsunakawa, Andrei Yahorau
Discussion: https://postgr.es/m/EDA4195584F5064680D8130B1CA91C45367328@G01JPEXMBYT04
Query planning is affected by a number of configuration options, and it
may be crucial to know which of those options were set to non-default
values. With this patch you can say EXPLAIN (SETTINGS ON) to include
that information in the query plan. Only options affecting planning,
with values different from the built-in default are printed.
This patch also adds auto_explain.log_settings option, providing the
same capability in auto_explain module.
Author: Tomas Vondra
Reviewed-by: Rafia Sabih, John Naylor
Discussion: https://postgr.es/m/e1791b4c-df9c-be02-edc5-7c8874944be0@2ndquadrant.com
This is useful to obtain a view of the different transaction types in an
application, regardless of the durations of the statements each runs.
Author: Adrien Nayrat
Reviewed-by: Masahiko Sawada, Hayato Kuroda, Andres Freund
This change makes it possible to specify sub-millisecond delays,
which work well on most modern platforms, though that was not true
when the cost-delay feature was designed.
To support this without breaking existing configuration entries,
improve guc.c to allow floating-point GUCs to have units. Also,
allow "us" (microseconds) as an input/output unit for time-unit GUCs.
(It's not allowed as a base unit, at least not yet.)
Likewise change the autovacuum_vacuum_cost_delay reloption to be
floating-point; this forces a catversion bump because the layout of
StdRdOptions changes.
This patch doesn't in itself change the default values or allowed
ranges for these parameters, and it should not affect the behavior
for any already-allowed setting for them.
Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us
This allows to set a lower log_min_duration_statement value without
incurring excessive log traffic (which reduces performance). This can
be useful to analyze workloads with lots of short queries.
Author: Adrien Nayrat
Reviewed-by: David Rowley, Vik Fearing
Discussion: https://postgr.es/m/c30ee535-ee1e-db9f-fa97-146b9f62caed@anayrat.info
Previously tables declared WITH OIDS, including a significant fraction
of the catalog tables, stored the oid column not as a normal column,
but as part of the tuple header.
This special column was not shown by default, which was somewhat odd,
as it's often (consider e.g. pg_class.oid) one of the more important
parts of a row. Neither pg_dump nor COPY included the contents of the
oid column by default.
The fact that the oid column was not an ordinary column necessitated a
significant amount of special case code to support oid columns. That
already was painful for the existing, but upcoming work aiming to make
table storage pluggable, would have required expanding and duplicating
that "specialness" significantly.
WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0).
Remove it.
Removing includes:
- CREATE TABLE and ALTER TABLE syntax for declaring the table to be
WITH OIDS has been removed (WITH (oids[ = true]) will error out)
- pg_dump does not support dumping tables declared WITH OIDS and will
issue a warning when dumping one (and ignore the oid column).
- restoring an pg_dump archive with pg_restore will warn when
restoring a table with oid contents (and ignore the oid column)
- COPY will refuse to load binary dump that includes oids.
- pg_upgrade will error out when encountering tables declared WITH
OIDS, they have to be altered to remove the oid column first.
- Functionality to access the oid of the last inserted row (like
plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed.
The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false)
for CREATE TABLE) is still supported. While that requires a bit of
support code, it seems unnecessary to break applications / dumps that
do not use oids, and are explicit about not using them.
The biggest user of WITH OID columns was postgres' catalog. This
commit changes all 'magic' oid columns to be columns that are normally
declared and stored. To reduce unnecessary query breakage all the
newly added columns are still named 'oid', even if a table's column
naming scheme would indicate 'reloid' or such. This obviously
requires adapting a lot code, mostly replacing oid access via
HeapTupleGetOid() with access to the underlying Form_pg_*->oid column.
The bootstrap process now assigns oids for all oid columns in
genbki.pl that do not have an explicit value (starting at the largest
oid previously used), only oids assigned later by oids will be above
FirstBootstrapObjectId. As the oid column now is a normal column the
special bootstrap syntax for oids has been removed.
Oids are not automatically assigned during insertion anymore, all
backend code explicitly assigns oids with GetNewOidWithIndex(). For
the rare case that insertions into the catalog via SQL are called for
the new pg_nextoid() function can be used (which only works on catalog
tables).
The fact that oid columns on system tables are now normal columns
means that they will be included in the set of columns expanded
by * (i.e. SELECT * FROM pg_class will now include the table's oid,
previously it did not). It'd not technically be hard to hide oid
column by default, but that'd mean confusing behavior would either
have to be carried forward forever, or it'd cause breakage down the
line.
While it's not unlikely that further adjustments are needed, the
scope/invasiveness of the patch makes it worthwhile to get merge this
now. It's painful to maintain externally, too complicated to commit
after the code code freeze, and a dependency of a number of other
patches.
Catversion bump, for obvious reasons.
Author: Andres Freund, with contributions by John Naylor
Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
Also, fix the pg_settings view to display source filename and line
number when invoked by a pg_read_all_settings member. This addition by
me (Álvaro).
Also, fix wording of the comment in GetConfigOption regarding the
restriction it implements, renaming the parameter for extra clarity.
Noted by Michaël.
These were all oversight in commit 25fff40798fc; backpatch to pg10,
where that commit first appeared.
Author: Laurenz Albe
Reviewed-by: Michaël Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/1519917758.6586.8.camel@cybertec.at
Code that prints out the contents of setconfig or proconfig arrays in
SQL format needs to handle GUC_LIST_QUOTE variables differently from
other ones, because for those variables, flatten_set_variable_args()
already applied a layer of quoting. The value can therefore safely
be printed as-is, and indeed must be, or flatten_set_variable_args()
will muck it up completely on reload. For all other GUC variables,
it's necessary and sufficient to quote the value as a SQL literal.
We'd recognized the need for this long ago, but mis-analyzed the
need slightly, thinking that all GUC_LIST_INPUT variables needed
the special treatment. That's actually wrong, since a valid value
of a LIST variable might include characters that need quoting,
although no existing variables accept such values.
More to the point, we hadn't made any particular effort to keep the
various places that deal with this up-to-date with the set of variables
that actually need special treatment, meaning that we'd do the wrong
thing with, for example, temp_tablespaces values. This affects dumping
of SET clauses attached to functions, as well as ALTER DATABASE/ROLE SET
commands.
In ruleutils.c we can fix it reasonably honestly by exporting a guc.c
function that allows discovering the flags for a given GUC variable.
But pg_dump doesn't have easy access to that, so continue the old method
of having a hard-wired list of affected variable names. At least we can
fix it to have just one list not two, and update the list to match
current reality.
A remaining problem with this is that it only works for built-in
GUC variables. pg_dump's list obvious knows nothing of third-party
extensions, and even the "ask guc.c" method isn't bulletproof since
the relevant extension might not be loaded. There's no obvious
solution to that, so for now, we'll just have to discourage extension
authors from inventing custom GUCs that need GUC_LIST_QUOTE.
This has been busted for a long time, so back-patch to all supported
branches.
Michael Paquier and Tom Lane, reviewed by Kyotaro Horiguchi and
Pavel Stehule
Discussion: https://postgr.es/m/20180111064900.GA51030@paquier.xyz
Without this fix, dropping a role can sometimes result in parallel
query failures in sessions that have used "SET ROLE" to assume the
dropped role, even if that setting isn't active any more.
Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me.
Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:
* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
than the expected column 33.
On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list. This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.
There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses. I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
Previously they were defined using multiples of XLogSegSize.
Remove GUC_UNIT_XSEGS. Introduce GUC_UNIT_MB
Extracted from patch series on XLogSegSize infrastructure.
Beena Emerson
Commit 88e982302 invented GUC_UNIT_XSEGS for min_wal_size and max_wal_size,
but neglected to make it display sensibly in pg_settings.unit (by adding a
case to the switch in GetConfigOptionByNum). Fix that, and adjust said
switch to throw a run-time error the next time somebody forgets.
In passing, avoid using a static buffer for the output string --- the rest
of this function pstrdup's from a local buffer, and I see no very good
reason why the units code should do it differently and less safely.
Per report from Otar Shavadze. Back-patch to 9.5 where the new unit type
was added.
Report: <CAG-jOyA=iNFhN+yB4vfvqh688B7Tr5SArbYcFUAjZi=0Exp-Lg@mail.gmail.com>
This allows convenient checking for existence of a GUC from SQL, which is
particularly useful when dealing with custom variables.
David Christensen, reviewed by Jeevan Chalke
As first committed, this view reported on the file contents as they were
at the last SIGHUP event. That's not as useful as reporting on the current
contents, and what's more, it didn't work right on Windows unless the
current session had serviced at least one SIGHUP. Therefore, arrange to
re-read the files when pg_show_all_settings() is called. This requires
only minor refactoring so that we can pass changeVal = false to
set_config_option() so that it won't actually apply any changes locally.
In addition, add error reporting so that errors that would prevent the
configuration files from being loaded, or would prevent individual settings
from being applied, are visible directly in the view. This makes the view
usable for pre-testing whether edits made in the config files will have the
desired effect, before one actually issues a SIGHUP.
I also added an "applied" column so that it's easy to identify entries that
are superseded by later entries; this was the main use-case for the original
design, but it seemed unnecessarily hard to use for that.
Also fix a 9.4.1 regression that allowed multiple entries for a
PGC_POSTMASTER variable to cause bogus complaints in the postmaster log.
(The issue here was that commit bf007a27ac unintentionally reverted
3e3f65973a, which suppressed any duplicate entries within
ParseConfigFp. However, since the original coding of the pg_file_settings
view depended on such suppression *not* happening, we couldn't have fixed
this issue now without first doing something with pg_file_settings.
Now we suppress duplicates by marking them "ignored" within
ProcessConfigFileInternal, which doesn't hide them in the view.)
Lesser changes include:
Drive the view directly off the ConfigVariable list, instead of making a
basically-equivalent second copy of the data. There's no longer any need
to hang onto the data permanently, anyway.
Convert show_all_file_settings() to do its work in one call and return a
tuplestore; this avoids risks associated with assuming that the GUC state
will hold still over the course of query execution. (I think there were
probably latent bugs here, though you might need something like a cursor
on the view to expose them.)
Arrange to run SIGHUP processing in a short-lived memory context, to
forestall process-lifespan memory leaks. (There is one known leak in this
code, in ProcessConfigDirectory; it seems minor enough to not be worth
back-patching a specific fix for.)
Remove mistaken assignment to ConfigFileLineno that caused line counting
after an include_dir directive to be completely wrong.
Add missed failure check in AlterSystemSetConfigFile(). We don't really
expect ParseConfigFp() to fail, but that's not an excuse for not checking.
This undoes a poorly-thought-out choice in commit 970a18687f, namely
to export guc.c's internal variable data_directory. The authoritative
variable so far as C code is concerned is DataDir; there is no reason for
anything except specific bits of GUC code to look at the GUC variable.
After yesterday's commits fixing the fsync-on-restart patch, the only
remaining misuse of data_directory was in AlterSystemSetConfigFile(),
which would be much better off just using a relative path anyhow: it's
less code and it doesn't break if the DBA moves the data directory of a
running system, which is a case we've taken some pains over in the past.
This is mostly cosmetic, so no need for a back-patch (and I'd be hesitant
to remove a global variable in stable branches anyway).
Instead of having a single knob (checkpoint_segments) that both triggers
checkpoints, and determines how many checkpoints to recycle, they are now
separate concerns. There is still an internal variable called
CheckpointSegments, which triggers checkpoints. But it no longer determines
how many segments to recycle at a checkpoint. That is now auto-tuned by
keeping a moving average of the distance between checkpoints (in bytes),
and trying to keep that many segments in reserve. The advantage of this is
that you can set max_wal_size very high, but the system won't actually
consume that much space if there isn't any need for it. The min_wal_size
sets a floor for that; you can effectively disable the auto-tuning behavior
by setting min_wal_size equal to max_wal_size.
The max_wal_size setting is now the actual target size of WAL at which a
new checkpoint is triggered, instead of the distance between checkpoints.
Previously, you could calculate the actual WAL usage with the formula
"(2 + checkpoint_completion_target) * checkpoint_segments + 1". With this
patch, you set the desired WAL usage with max_wal_size, and the system
calculates the appropriate CheckpointSegments with the reverse of that
formula. That's a lot more intuitive for administrators to set.
Reviewed by Amit Kapila and Venkata Balaji N.
Replace the if-switch-case constructs with two conversion tables,
containing all the supported conversions between human-readable unit
strings and the base units used in GUC variables. This makes the code
easier to read, and makes adding new units simpler.
Since this is not something that a user should change,
pg_config_manual.h was an inappropriate place for it.
In initdb.c, remove the use of the macro, because utils/guc.h can't be
included by non-backend code. But we hardcode all the other
configuration file names there, so this isn't a disaster.
Previously the maximum size of GIN pending list was controlled only by
work_mem. But the reasonable value of work_mem and the reasonable size
of the list are basically not the same, so it was not appropriate to
control both of them by only one GUC, i.e., work_mem. This commit
separates new GUC, pending_list_cleanup_size, from work_mem to allow
users to control only the size of the list.
Also this commit adds pending_list_cleanup_size as new storage parameter
to allow users to specify the size of the list per index. This is useful,
for example, when users want to increase the size of the list only for
the GIN index which can be updated heavily, and decrease it otherwise.
Reviewed by Etsuro Fujita.
This new GUC context option allows GUC parameters to have the combined
properties of PGC_BACKEND and PGC_SUSET, ie, they don't change after
session start and non-superusers can't change them. This is a more
appropriate choice for log_connections and log_disconnections than their
previous context of PGC_BACKEND, because we don't want non-superusers
to be able to affect whether their sessions get logged.
Note: the behavior for log_connections is still a bit odd, in that when
a superuser attempts to set it from PGOPTIONS, the setting takes effect
but it's too late to enable or suppress connection startup logging.
It's debatable whether that's worth fixing, and in any case there is
a reasonable argument for PGC_SU_BACKEND to exist.
In passing, re-pgindent the files touched by this commit.
Fujii Masao, reviewed by Joe Conway and Amit Kapila
When running several postgres clusters on one OS instance it's often
inconveniently hard to identify which "postgres" process belongs to
which postgres instance.
Add the cluster_name GUC, whose value will be included as part of the
process titles if set. With that processes can more easily identified
using tools like 'ps'.
To avoid problems with encoding mismatches between postgresql.conf,
consoles, and individual databases replace non-ASCII chars in the name
with question marks. The length is limited to NAMEDATALEN to make it
less likely to truncate important information at the end of the
status.
Thomas Munro, with some adjustments by me and review by a host of people.
data_directory could be set both in postgresql.conf and postgresql.auto.conf so far.
This could cause some problematic situations like circular definition. To avoid such
situations, this commit forbids a user to set data_directory in postgresql.auto.conf.
Backpatch this to 9.4 where ALTER SYSTEM command was introduced.
Amit Kapila, reviewed by Abhijit Menon-Sen, with minor adjustments by me.
This reverts commit ee1e5662d8, as well as
a remarkably large number of followup commits, which were mostly concerned
with the fact that the implementation didn't work terribly well. It still
doesn't: we probably need some rather basic work in the GUC infrastructure
if we want to fully support GUCs whose default varies depending on the
value of another GUC. Meanwhile, it also emerged that there wasn't really
consensus in favor of the definition the patch tried to implement (ie,
effective_cache_size should default to 4 times shared_buffers). So whack
it all back to where it was. In a followup commit, I'll do what was
recently agreed to, which is to simply change the default to a higher
value.