indexing

问题 Lets say you have a collection with a field called "primary_key", {"primary_key":"1234", "name":"jimmy", "lastname":"page"} and I have an index on "primary_key". This collection has millions of rows, I want to see how expensive is to change primary_key for one of the records. Does it trigger a reindex of the entire table? or does it just reindex the changed record? in either case is that expensive to do? 回答1: Updating an indexed field in mongodb causes an update of the index (or indices if

问题 This is the second part of my question. So I have the following table, CREATE TABLE public.main_transaction ( id integer NOT NULL DEFAULT nextval('main_transaction_id_seq'::regclass), profile_id integer NOT NULL, request_no character varying(18), user_id bigint, ..... CONSTRAINT main_transaction_pkey PRIMARY KEY (id), CONSTRAINT fk_main_transaction_user_id FOREIGN KEY (user_id) REFERENCES public.jhi_user (id) MATCH SIMPLE ON UPDATE NO ACTION ON DELETE NO ACTION, REFERENCES public.main_profile

问题 I am indexing a collection of xml document with the next structure: <mydoc> <id>1234</id> <name>Some Name</name> <experiences> <experience years="10" type="Java"/> <experience years="4" type="Hadoop"/> <experience years="1" type="Hbase"/> </experiences> </mydoc> Is there any way to create solr index so that it would support the next query: find all docs with experience type "Hadoop" and years>=3 So far my best idea is to put delimited years||type into multiValued string field, search for all

问题 I have a data.table that resembles the one below. tab <- data.table(a = c(NA, 42190, NA), b = c(42190, 42190, NA), c = c(40570, 42190, NA)) tab a b c 1: NA 42190 40570 2: 42190 42190 42190 3: NA NA NA Upon specification of a vector of row indices, and a vector of column indices, I would like a vector returned containing the points in tab corresponding to the specified vector of row indices and column indices. For example, suppose I wanted to get the diagonal elements in tab . I would specify

问题 I have a bunch of rows and 25 columns in a worksheet, and need to find the value in the 4th column based on columns B and C using VBA. I am using a combination of index and multiple condition match functions. I tried to follow along via https://www.mrexcel.com/forum/showthread.php?650832-VBA-Multiple-Criteria-Index-Match and pass an integer variable into vba array formula to no avail. I made this macro which works: Sub VariablesInArrayFormula() SA = "Apples" C1 = "Oranges" Range("D27").Select

问题 I have a bunch of rows and 25 columns in a worksheet, and need to find the value in the 4th column based on columns B and C using VBA. I am using a combination of index and multiple condition match functions. I tried to follow along via https://www.mrexcel.com/forum/showthread.php?650832-VBA-Multiple-Criteria-Index-Match and pass an integer variable into vba array formula to no avail. I made this macro which works: Sub VariablesInArrayFormula() SA = "Apples" C1 = "Oranges" Range("D27").Select

问题 I am using Matlab R2014a. I have a 3-dimensional M x N x M matrix A. I would like a vectorized way to extract a 2 dimensional matrix B from it, such that for each i,j I have B(i,j)=A(i,j,g(i,j)) where g is a 2-dimensional index matrix of size M x N, i.e. with integral values in {1,2,...,M}. The context is that I am representing a function A(k,z,k') as a 3-dimensional matrix, the function g(k,z) as a 2-dimensional matrix, and I would like to compute the function h(k,z)=f(k,z,g(k,z)) This seems

问题 I have a list of floats generated from a data structure which is a list of dictionaries - i.e. I've iterated over the whole list and selected for certain values in the given dictionary. Now, I want to actually do something with these data points, for which I need some reference to the original position. I tried to simply use the data point as a key, but after trying and failing I did some digging and realized that floats aren't precisely represented due to the way computers work. So, what I

问题 I have started to work on my first Java program, which is a simple calculator, however I get an error claiming that my array is out of bounds. I have tried to debug it to see where and why that is so, as well as following the code on paper, both of which display the results that I would expect and wish for. Therefore, I can not see where the problem actually lies. The code is not complete. According to the debugger, the error occurs at this line: answer = outputNum.get(operationIndex) *

问题 This question already has answers here : How to find all occurrences of an element in a list? (15 answers) Closed 5 months ago . I guess the heading is self-explanatory, still, I'll make myself more clear. I've to find the indexes of every occurrence of a character in a string. For example, word = "banana" def indexes(x, word): #some code return (list of indexes of x character in the word) output: indexes('a', word) >> [1, 3, 5] How do I get this result? 回答1: Try this: word = "banana" def