MySQL Forums
Forum List  »  Optimizer & Parser

Re: Optimizing ORDER BY any ideas?
Posted by: Marc Van Olmen
Date: September 10, 2005 07:30AM

Hi Jay.

Side question:
How you come to the conclusion between index *scan* and seek, explained in your book?

Anyway I remember now that I added before an index for T_PROPERTY but with the new import I forgot. So I added it now like you suggested but it doesn't show much difference:

Create Table: CREATE TABLE `T_PROPERTY` (
`PRY_PHOTO` char(80) default NULL,
`PRY_LNK_CREATE_USER` int(11) NOT NULL,
`PRY_LNK_IMMO_PACKET` int(11) default NULL,
`PRY_LNK_IMMO_OFFER` int(11) default NULL,
`PRY_LNK_MODIFIED_USER` int(11) NOT NULL,
`PRY_MODIFIED_DATE` datetime NOT NULL,
`PRY_CREATE_DATE` datetime NOT NULL,
`PRY_LNK_SALES_ORDER_ITEM` int(11) NOT NULL,
`PRY_CONTACT` char(80) default NULL,
`PRY_DESCRIPTION` varchar(1624) default NULL,
`PRY_INDEX` int(11) NOT NULL auto_increment,
`PRY_EXPORT_TELETEXT` varchar(1624) default NULL,
`PRY_MUSICTEXT` varchar(1624) default NULL,
`PRY_PRINT_INTRODUCTION` varchar(1624) default NULL,
`PRY_EXPORT_MUSICTEXT` varchar(1624) default NULL,
`PRY_PRINT_TITLE` varchar(1624) default NULL,
`PRY_PRINT_FINAL_TEXT` varchar(1624) default NULL,
`PRY_PRINT_FINAL_SMALL` varchar(1624) default NULL,
`PRY_TELETEXT` varchar(1624) default NULL,
`PRY_EXPORT_ADDRESS` char(80) default NULL,
`PRY_LNK_PROPERTY_STATUS` int(11) default NULL,
`PRY_EXPORT_TYPE` char(80) default NULL,
`PRY_EXPORT_LAYOUT` varchar(1624) default NULL,
`PRY_EXPORT_CITY` char(80) default NULL,
`PRY_EXPORT_VISITINFO` varchar(1624) default NULL,
`PRY_SOLD_DATE` date default NULL,
`PRY_LNK_PROPERTY_SALES_LABEL` int(11) default NULL,
`PRY_EXPORT_SALES_COMMENT` char(80) default NULL,
`PRY_CONTACT_PHONE` char(80) default NULL,
`PRY_SMS` varchar(512) default NULL,
UNIQUE KEY `PRY_INDEX` (`PRY_INDEX`),
KEY `PRY_PHOTO` (`PRY_PHOTO`),
KEY `PRY_SOLD_DATE` (`PRY_SOLD_DATE`),
KEY `PRY_LNK_PROPERTY_SALES_LABEL` (`PRY_LNK_PROPERTY_SALES_LABEL`),
KEY `PRY_LNK_SALES_ORDER_ITEM_2` (`PRY_LNK_SALES_ORDER_ITEM`,`PRY_EXPORT_CITY`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8


Now the queries again first the

NO ORDER BY


*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: T_PROPERTY
type: index
possible_keys: PRY_LNK_SALES_ORDER_ITEM_2
key: PRY_LNK_SALES_ORDER_ITEM_2
key_len: 245
ref: NULL
rows: 5626
Extra: Using index; Using temporary
*************************** 2. row ***************************
id: 1
select_type: SIMPLE
table: T_SCHEDULE_ITEM
type: ref
possible_keys: SCI_FINISHED_DATE,SCI_START_DATE,SCI_LNK_CHANNEL,SCI_LNK_SALES_ORDER_ITEM,SCI_LNK_MEDIUM
key: SCI_LNK_SALES_ORDER_ITEM
key_len: 4
ref: tvplanner4.T_PROPERTY.PRY_LNK_SALES_ORDER_ITEM
rows: 4
Extra: Using where
*************************** 3. row ***************************
id: 1
select_type: SIMPLE
table: T_SALES_ORDER_ITEM
type: eq_ref
possible_keys: SOI_INDEX,SOI_LNK_SALES_ORDER,SOI_LNK_PRODUCT
key: SOI_INDEX
key_len: 4
ref: tvplanner4.T_SCHEDULE_ITEM.SCI_LNK_SALES_ORDER_ITEM
rows: 1
Extra: Using where
*************************** 4. row ***************************
id: 1
select_type: SIMPLE
table: T_SALES_ORDER
type: eq_ref
possible_keys: SAO_INDEX
key: SAO_INDEX
key_len: 4
ref: tvplanner4.T_SALES_ORDER_ITEM.SOI_LNK_SALES_ORDER
rows: 1
Extra: Using index
*************************** 5. row ***************************
id: 1
select_type: SIMPLE
table: T_PROGRAM_PRODUCT
type: ref
possible_keys: PMP_LNK_PROGRAM,PMP_LNK_CHANNEL,PMP_LNK_PRODUCT
key: PMP_LNK_PRODUCT
key_len: 4
ref: tvplanner4.T_SALES_ORDER_ITEM.SOI_LNK_PRODUCT
rows: 2
Extra: Using where; Distinct


The query itself takes 0.1 seconds


with ORDER BY

*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: T_PROPERTY
type: index
possible_keys: PRY_LNK_SALES_ORDER_ITEM_2
key: PRY_LNK_SALES_ORDER_ITEM_2
key_len: 245
ref: NULL
rows: 5626
Extra: Using index; Using temporary; Using filesort
*************************** 2. row ***************************
id: 1
select_type: SIMPLE
table: T_SCHEDULE_ITEM
type: ref
possible_keys: SCI_FINISHED_DATE,SCI_START_DATE,SCI_LNK_CHANNEL,SCI_LNK_SALES_ORDER_ITEM,SCI_LNK_MEDIUM
key: SCI_LNK_SALES_ORDER_ITEM
key_len: 4
ref: tvplanner4.T_PROPERTY.PRY_LNK_SALES_ORDER_ITEM
rows: 4
Extra: Using where
*************************** 3. row ***************************
id: 1
select_type: SIMPLE
table: T_SALES_ORDER_ITEM
type: eq_ref
possible_keys: SOI_INDEX,SOI_LNK_SALES_ORDER,SOI_LNK_PRODUCT
key: SOI_INDEX
key_len: 4
ref: tvplanner4.T_SCHEDULE_ITEM.SCI_LNK_SALES_ORDER_ITEM
rows: 1
Extra: Using where
*************************** 4. row ***************************
id: 1
select_type: SIMPLE
table: T_SALES_ORDER
type: eq_ref
possible_keys: SAO_INDEX
key: SAO_INDEX
key_len: 4
ref: tvplanner4.T_SALES_ORDER_ITEM.SOI_LNK_SALES_ORDER
rows: 1
Extra: Using index
*************************** 5. row ***************************
id: 1
select_type: SIMPLE
table: T_PROGRAM_PRODUCT
type: ref
possible_keys: PMP_LNK_PROGRAM,PMP_LNK_CHANNEL,PMP_LNK_PRODUCT
key: PMP_LNK_PRODUCT
key_len: 4
ref: tvplanner4.T_SALES_ORDER_ITEM.SOI_LNK_PRODUCT
rows: 2
Extra: Using where; Distinct

The Query itself takes 0.9 seconds

T_PROPERTY,T_SALES_ORDER_ITEM,T_SALES_ORDER each have less then 6000 records, T_PROGRAM_PRODUCT has 4 records and T_SCHEDULE_ITEM has about 40000 records not huge numbers. I'm running on a Dual 2.5ghz G5 processor.


We are infact are back now to the initial reason why I started this query because I was surprised that the query took so long because I indexed PRY_EXPORT_CITY initialy

Options: ReplyQuote


Subject
Views
Written By
Posted
5024
September 06, 2005 05:35PM
2802
September 06, 2005 06:39PM
2967
September 06, 2005 08:30PM
2734
September 06, 2005 09:18PM
2719
September 07, 2005 07:10AM
2683
September 07, 2005 06:28PM
2741
September 07, 2005 08:55PM
2571
September 08, 2005 08:28AM
2673
September 08, 2005 11:12PM
2671
September 09, 2005 10:00AM
2612
September 09, 2005 10:22AM
2619
September 09, 2005 10:03PM
Re: Optimizing ORDER BY any ideas?
2849
September 10, 2005 07:30AM
3241
September 10, 2005 09:22AM
2635
September 12, 2005 02:45PM
2562
September 12, 2005 04:41PM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.