MarkLogic interview: What is DLS library in MarkLogic?

 

Q.1. What is DLS library in MarkLogic?

Ans: 
   DLS library is used for maintain the versions of managed document in the Marklogic server. So that your data will be intact in marklogic while performing any insert/update/delete operation on the document. Marklogic create two copy every time, one is final copy after updating document and second old version copy.   

Example: You want to insert data into DB with '/books.xml'.

You have inserted data with help of dls:document-insert-and-manage() and this function creates two uri: one is  '/books.xml',  and second is '/books_version1.xml'  

Comments

Post a Comment

Popular posts from this blog

What is universal index and range index?

  Universal index : The universal index is the indexing process of MarkLogic that Marklogic performs automatically when data is loaded into MarkLogic. By default MarkLogic indexing below universal index: Word Indexing Phrase Indexing Relationship Indexing Value Indexing Word and Phrase Indexing Inverted index: An inverted index inverts the document-word relationship into a word-documents relationship.  Each entry in the inverted index is called a  term list .  Range Index:  Ranges index is also an indexing process in Marklogic but this index is created by the developer based on project requirements. When we need a fast result in the project, we create ranges indexes.   Path range index Element range index Element attribute range index etc...
Read more

What is the basic difference between xdmp:spawn and xdmp:invoke a function in Marklogic.

 Aha..... Before understanding  xdmp:spawn-function and xdmp:invoke-function in Marklogic, we need to understand synchronous & asynchronous terms. Also, we need to know what is the main server, task server, and Transactions in the Marklogic. So I'm posting here the simple definition of each term that I mentioned here.  Synchronous and Asynchronous Task: Synchronous : In synchronous operations tasks are performed one at a time and you can't move the following task until the current task is finished. Asynchronous : In asynchronous operations, you can move to another task before the previous one finishes. Main Server : Task server: Transactions: Now,  We need to know what  asynchronous  functions &  asynchronous  functions in Marklogic are: Asynchronous Functions: xdmp:spawn : Place the specified module/query on the task queue for evaluation. This function places the specified module in the task queue to be processed. The module will be eva...
Read more

MarkLogic server architecture.

Image
There are two layers that work in the complete Marklogic application.  The first is the  Data layer . Second  Query layer .   In the  Data layer : Marklogic stores data (in any format, XML, JSON, text, binary data, semantics ) at the bottom of the data layer. On bottom data, Marklogic creates universal index and range index also if defined. Marklogic also creates a cache and journal in the data layer. In all of this, there is also a transaction controller in the data layers. On came in the second layer.  This is the query layer where we evaluate the x query programs.
Read more