Re: [HACKERS] Fractions in GUC variables
On Tue, Dec 16, 2014 at 12:19 AM, Peter Eisentraut pete...@gmx.net wrote: On 12/15/14 8:56 AM, Heikki Linnakangas wrote: Overall, I feel that this isn't really worth the trouble. We use fractions consistently now, so there isn't much room for confusion over what the current values mean. Using a percentage might be more familiar for some people, but OTOH you'll have to get used to the fractions anyway, unless we change the default output format too, and I'm not in favour of doing that. I suggest that we just drop this, and remove the TODO item. Agreed. The patch is sound as far as it goes (I might be inclined to accept whitespace between number and % sign), but given the above points and the original reason for it having been eliminated, I'm inclined to drop it. +1. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On 12/07/2014 09:48 PM, John Gorman wrote: This patch implements the first wiki/Todo Configuration Files item Consider normalizing fractions in postgresql.conf, perhaps using '%'. The Fractions in GUC variables discussion is here. http://www.postgresql.org/message-id/467132cf.9020...@enterprisedb.com Ah, flash from the past :-). Thanks for looking into this. The bgwriter_lru_percent and bgwriter_all_percent settings are gone now, so the original reason to do this is gone. We consistently use fractions in the GUCs now. This patch implements expressing GUC variables as percents in postgresql.conf. autovacuum_vacuum_scale_factor = 20% # percent of table size before vacuum autovacuum_analyze_scale_factor = 10% # percent of table size before analyze As you can see the postgresql.conf file and the documentation read more naturally. I added a regression test to guc.sql. The sql interface also accepts both numeric and percent forms although the percent form must be quoted because '%' is an operator. show cursor_tuple_fraction; -- 10% set cursor_tuple_fraction = .15; -- 15% set cursor_tuple_fraction = '33%'; -- 33% I tagged four configuration variables to display as percents. I'm not sure I agree that percentages are better than fractions. I'd vote a -0.5 for changing the default display format. There isn't much harm in accepting them as a secondary format, though. We should only accept percentages for settings where that makes sense. It is sensible for most of the PGC_REAL settings, but not so much for geqo_selection_bias or seed, for example. Overall, I feel that this isn't really worth the trouble. We use fractions consistently now, so there isn't much room for confusion over what the current values mean. Using a percentage might be more familiar for some people, but OTOH you'll have to get used to the fractions anyway, unless we change the default output format too, and I'm not in favour of doing that. I suggest that we just drop this, and remove the TODO item. - Heikki -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On 12/15/14 8:56 AM, Heikki Linnakangas wrote: show cursor_tuple_fraction; -- 10% set cursor_tuple_fraction = .15; -- 15% set cursor_tuple_fraction = '33%'; -- 33% I tagged four configuration variables to display as percents. I'm not sure I agree that percentages are better than fractions. I'd vote a -0.5 for changing the default display format. There isn't much harm in accepting them as a secondary format, though. Agreed with not changing the default output. Everyone is used to it, and there is no reason why the percent output would be intrinsically better. We should only accept percentages for settings where that makes sense. It is sensible for most of the PGC_REAL settings, but not so much for geqo_selection_bias or seed, for example. Right. But then this feature would get more complicated, as opposed to supposedly making things simpler. Overall, I feel that this isn't really worth the trouble. We use fractions consistently now, so there isn't much room for confusion over what the current values mean. Using a percentage might be more familiar for some people, but OTOH you'll have to get used to the fractions anyway, unless we change the default output format too, and I'm not in favour of doing that. I suggest that we just drop this, and remove the TODO item. Agreed. The patch is sound as far as it goes (I might be inclined to accept whitespace between number and % sign), but given the above points and the original reason for it having been eliminated, I'm inclined to drop it. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On Mon, Dec 15, 2014 at 10:19:19AM -0500, Peter Eisentraut wrote: Overall, I feel that this isn't really worth the trouble. We use fractions consistently now, so there isn't much room for confusion over what the current values mean. Using a percentage might be more familiar for some people, but OTOH you'll have to get used to the fractions anyway, unless we change the default output format too, and I'm not in favour of doing that. I suggest that we just drop this, and remove the TODO item. Agreed. The patch is sound as far as it goes (I might be inclined to accept whitespace between number and % sign), but given the above points and the original reason for it having been eliminated, I'm inclined to drop it. TODO item removed. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On 12/7/14, 1:48 PM, John Gorman wrote: This patch implements the first wiki/Todo Configuration Files item Consider normalizing fractions in postgresql.conf, perhaps using '%'. FWIW, I've reviewed this (should have read the thread first :/). It looks clean, passes make check and works as advertised. I also looked at what config options were set to be % and they make sense. Looking for .[0-9] in postgresql.conf, the only GUCs I saw where % didn't make sense was the two geco GUCs Heikki mentioned. One thing I don't like is the need to wrap a %-based SET in quotes, but we need to do that for all GUCs that include units, so presumably there's no good way around it. -- Jim Nasby, Data Architect, Blue Treble Consulting Data in Trouble? Get it in Treble! http://BlueTreble.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Fractions in GUC variables
This patch implements the first wiki/Todo Configuration Files item Consider normalizing fractions in postgresql.conf, perhaps using '%'. The Fractions in GUC variables discussion is here. http://www.postgresql.org/message-id/467132cf.9020...@enterprisedb.com This patch implements expressing GUC variables as percents in postgresql.conf. autovacuum_vacuum_scale_factor = 20% # percent of table size before vacuum autovacuum_analyze_scale_factor = 10% # percent of table size before analyze As you can see the postgresql.conf file and the documentation read more naturally. I added a regression test to guc.sql. The sql interface also accepts both numeric and percent forms although the percent form must be quoted because '%' is an operator. show cursor_tuple_fraction; -- 10% set cursor_tuple_fraction = .15; -- 15% set cursor_tuple_fraction = '33%'; -- 33% I tagged four configuration variables to display as percents. The attached patch applies cleanly against master and passes all regression tests including two new tests in guc.sql. guc_percent-v1.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On 12/07/2014 11:48 AM, John Gorman wrote: This patch implements the first wiki/Todo Configuration Files item Consider normalizing fractions in postgresql.conf, perhaps using '%'. The Fractions in GUC variables discussion is here. Oh, this is nice! Thanks for working on it. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
On Mon, Dec 8, 2014 at 4:48 AM, John Gorman johngorm...@gmail.com wrote: The attached patch applies cleanly against master and passes all regression tests including two new tests in guc.sql. Please be sure to register your patch to the upcoming commit fest, this way it will not fall into oblivion and will get some feedback: https://commitfest.postgresql.org/action/commitfest_view?id=25 -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
Added to TODO: o Consider normalizing fractions in postgresql.conf, perhaps using '%' http://archives.postgresql.org/pgsql-hackers/2007-06/msg00550.php --- Heikki Linnakangas wrote: We have these GUC variables that define a fraction of something: #autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before # vacuum #autovacuum_analyze_scale_factor = 0.1# fraction of rel size before # analyze #bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round #bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round Autovacuum settings use fractions, and bgwriter settings use a percentage. Fortunately these settings are not related so there's not too much potential for confusion, but it seems we should have a common way to define settings like that. A nice way would be that the base unit would be a fraction, like in the autovacuum settings, but you could add a %-sign to give it as a percent, just like you can use KB/MB etc. I'm not sure if we can do anything for those without breaking backwards-compatibility, though. Any ideas? The load distributed checkpoints patch adds one more GUC variable like. I'm inclined to follow the example of the bgwriter settings because it's more closely related to them, though I like the autovacuum style more. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org -- Bruce Momjian [EMAIL PROTECTED]http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Fractions in GUC variables
This has been saved for the 8.4 release: http://momjian.postgresql.org/cgi-bin/pgpatches_hold --- Heikki Linnakangas wrote: We have these GUC variables that define a fraction of something: #autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before # vacuum #autovacuum_analyze_scale_factor = 0.1# fraction of rel size before # analyze #bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round #bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round Autovacuum settings use fractions, and bgwriter settings use a percentage. Fortunately these settings are not related so there's not too much potential for confusion, but it seems we should have a common way to define settings like that. A nice way would be that the base unit would be a fraction, like in the autovacuum settings, but you could add a %-sign to give it as a percent, just like you can use KB/MB etc. I'm not sure if we can do anything for those without breaking backwards-compatibility, though. Any ideas? The load distributed checkpoints patch adds one more GUC variable like. I'm inclined to follow the example of the bgwriter settings because it's more closely related to them, though I like the autovacuum style more. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org -- Bruce Momjian [EMAIL PROTECTED] http://momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] Fractions in GUC variables
On Jun 14, 2007, at 7:21 AM, Heikki Linnakangas wrote: We have these GUC variables that define a fraction of something: #autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before # vacuum #autovacuum_analyze_scale_factor = 0.1 # fraction of rel size before # analyze #bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round #bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round Autovacuum settings use fractions, and bgwriter settings use a percentage. Fortunately these settings are not related so there's not too much potential for confusion, but it seems we should have a common way to define settings like that. A nice way would be that the base unit would be a fraction, like in the autovacuum settings, but you could add a %-sign to give it as a percent, just like you can use KB/MB etc. I'm not sure if we can do anything for those without breaking backwards-compatibility, though. Any ideas? The load distributed checkpoints patch adds one more GUC variable like. I'm inclined to follow the example of the bgwriter settings because it's more closely related to them, though I like the autovacuum style more. We could create bgwrite_*_fraction (portion?) and deprecate bgwriter_*_percent... -- Jim Nasby[EMAIL PROTECTED] EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
[HACKERS] Fractions in GUC variables
We have these GUC variables that define a fraction of something: #autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before # vacuum #autovacuum_analyze_scale_factor = 0.1 # fraction of rel size before # analyze #bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round #bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round Autovacuum settings use fractions, and bgwriter settings use a percentage. Fortunately these settings are not related so there's not too much potential for confusion, but it seems we should have a common way to define settings like that. A nice way would be that the base unit would be a fraction, like in the autovacuum settings, but you could add a %-sign to give it as a percent, just like you can use KB/MB etc. I'm not sure if we can do anything for those without breaking backwards-compatibility, though. Any ideas? The load distributed checkpoints patch adds one more GUC variable like. I'm inclined to follow the example of the bgwriter settings because it's more closely related to them, though I like the autovacuum style more. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
