In this article I will explain what a MAKEDEP hint is, how and when, why it should be used in Teiid. What: MAKEDEP is query hint. When a query hint is defined in the SQL query it influences the Teiid query planner to optimize the query in a way that is driven by the user. MAKEDEP means "make this as a dependent join". What is a Dependent Join? For example if we have query like: SELECT * FROM X INNER JOIN Y ON X.PK = Y.FK Where the data for X, and Y are coming from two different sources like Oracle and WebService in Teiid, so in relational algebra you can represent above query as Here the result tuples from node X and node Y are being simultaneously fetched by Teiid query engine, then it joins the both the results inside Teiid engine based on the specified X.PK = Y.PK condition and returns the filtered resulted to the user. simple.. Now, what if, if X table has 5 rows and Y table has 100K rows? In order to do the JOIN naively Teiid need sto read all the 5
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