In most use cases, indexing the data from scratch during every indexation doesn't make sense. Why index your 1,00,000 documents when only 1,000 were modified or added? This is where the Solr Data Import Handler delta queries come in handy. Using them, we can index our data incrementally. This recipe will show you how to set up the Data Import Handler to use delta queries and index data in an incremental way.
Refer to the Indexing data from a database using Data Import Handler recipe in this chapter to get to know the basics of the Data Import Handler configuration. I assume that Solr is set up according to the description given in the mentioned recipe.
We will reuse parts of the configuration shown in the Indexing data from a database using Data Import Handler recipe in this chapter, and we will modify it. Execute the following steps:
The first thing you should do is add an additional column to the tables you use, a column that will specify...