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Editor to share with you how to synchronize the data in CouchDB to a relational database, I believe most people do not know much about it, so share this article for your reference. I hope you will gain a lot after reading this article. Let's learn about it together.

The problem with CouchDB

First of all, the author does not want to do this for the reasons we mentioned above. It's because CouchDB can't meet some of their needs. We know that CouchDB needs to define a View in advance for the desired query operation, and then all query operations are actually done on this View. So if the data query conditions you are going to do are very uncertain, it may be troublesome to use CouchDB.

The author considers two methods:

1. You can imagine the waste of resources by creating different View- permutation and combination problems for all possible query orders.

two。 Set up a View and store multiple copies of fields in different order-this is about the same waste as above

In fact, this requirement is the strength of relational databases. Almost all relational databases support querying data in any order, and there is no need to pre-determine the mode of query. As long as the corresponding index is established for performance.

How to synchronize the data in CouchDB to a relational database

Solution

The final choice is to use CouchDB's ChangeNotifications mechanism, which allows listening to data, and when there is a write operation, the corresponding callback function will be executed to complete the operation you want to do.

The specific implementation process is as follows: (it is mainly implemented by couchdbkit and django)

1Connectto change feedforward-Connect to the _ changes interface for data modification operations

2Foreverylineinthe feed-perform the following two steps on each piece of data

-2.1 Determineifyouwanttoactonit-determine whether the data is to be processed by filtering rules

-2.2 (Ifyes) dosomethingaboutit- if it needs to be processed, then deal with it accordingly.

The above is all the contents of the article "how to synchronize data in CouchDB to a relational database". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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