indexing

问题 I have a user table that has many columns, it looks roughly like this: dname: { type: string(255), notnull: true } email: { type: string(255), notnull: true, unique: true } email_code: { type: string(255) } email_confirmed: { type: boolean, default: false } profile_filled: { type: boolean, default: false } password: { type: string(255), notnull: true } image_id: { type: integer } gender: { type: enum, values: [male, female] } description: { type: string } dob: { type: date } height: { type:

问题 I'm looking for being able to find rows matching approximatively (let's say within 20 meters) given from and to points. It works but it doesn't use index. I'm trying to take advantage of Spatial index on this table but it doesn't seems to be used (Explain command give me "possible_keys" = null). With the following: mysql 5.7.17 table: CREATE TABLE `geoDirections` ( `id` int(11) NOT NULL, `from` point NOT NULL, `to` point NOT NULL, ) ENGINE=InnoDB; ALTER TABLE `geoDirections` ADD PRIMARY KEY (

问题 Im trying to iterate over a list in windows batch file, using the the different numbers within different lists as parameters in each iteration. set input_image_list=(1 2 3 4 5 6 7 8 9 ) set output_image_list = (2 3 4 5 6 7 8 9 10) set next_needed_image = (002 003 004 005 006 007 008 009 010) FOR %%A IN (2 3 4 5 6 7 8 9 10) DO python batchLayer4ThirdVideo.py --input_image !input_image_list[%%A]! --next_undreamed_image !next_needed_image[%%A]! --output_image %%A but the indexing of the lists

问题 I know, when we use a covering index, sql server uses only index seek(nonclustered) or index scan (nonclustered) operator in execution plan without retrieving data by lookup operator. But why is it possible not to look up values in clustered index? Nonclustered index doesn't store data on leaf level so regardless the number of columns it contains it has to ask clustered index to return data rows so it should be lookup operator in execution plan. Am I right? I've read https://www.red-gate.com

问题 I have built a SOLR Index which has the image thumbnail urls that I want to render an image along with the search results. The problem is that those images can run into millions and I think storing the images in index as binary data would make the index humongous. I am seeking guidance on how to efficiently store those images after rendering them from the URLs , should I use the plain file system and have them rendered by tomcat , or should I use a JCR repository like Apache Jackrabbit ? Any

问题 I'm using the impressionist gem for a Ruby on Rails based website. Our database is mysql. The impressions table is at about 2M records, which should pose no problem for MySql. The table size is 800M which is beginning to tax our servers. The data size of the table is 200M and the index size is 600M. Most of the indexes were predefined by the gem. Is there a way to figure out if any of these indexes are being used or can be deleted? 1,310,855,040 controlleraction_session_index 1,310,855,040

问题 I'm using Access to iterate through a table, finding relevant information and bringing it together in a master table. It loads up both recordsets, starts iterating through rsImport (Local <1000 row table), for each rsImport row, it looks to see if is a row that matches the UniqueRef in rsRecords, which it will then eithe update or add if it doens't exist. F8 stepping through the complete code it actually pauses when it des the rsRecords.findfirst. If I remove the DateofAction part, it speeds

问题 In ElasticSearch 5.6, I have created multiple indices of the same 15k documents. Specifically, 4 that all share the same mapping, settings, and content. 3 of the 4 had index sizes ~1.0 GB. index_1 of the 4 has a size of 52 MB. I've compared searches across the 4 indices, and index_1 returns less documents than the others for identical searches. I've seen anywhere from 1% to 80% less documents per query. At this point, I don't trust the docs.count or the store.size_in_bytes on index_1 or the

问题 I'm using Neo4j 3.0.5. My query looks as follows: MATCH (cd:ConnectionDay)-[c:Connection]->() WHERE id(cd)= { id } AND c.departure <= { departure } RETURN c In my graph, the number of Connection relations is very high and I'm looking for a way to speed up the retrieval. Is there a way to create an index for the departure property? I'm using the Embedded Java API anyway, so solutions that aren't using Cypher are ok, too. 回答1: Aside: It is not recommended that you use native neo4j IDs to find

问题 My data is organized in a dataframe: import pandas as pd import numpy as np data = {'Col1' : [4,5,6,7], 'Col2' : [10,20,30,40], 'Col3' : [100,50,-30,-50], 'Col4' : ['AAA', 'BBB', 'AAA', 'CCC']} df = pd.DataFrame(data=data, index = ['R1','R2','R3','R4']) Which looks like this (only much bigger): Col1 Col2 Col3 Col4 R1 4 10 100 AAA R2 5 20 50 BBB R3 6 30 -30 AAA R4 7 40 -50 CCC My algorithm loops through this table rows and performs a set of operations. For cleaness/lazyness sake, I would like