A data index method and system based on full cost calculation

Abstract

The invention discloses a method and system of data indexing based on the full cost calculation, and relates to the field of data indexing application calculation. The method of data indexing based on the full cost calculation comprises the steps of detecting indexes which can be used, judging the number of indexes which can be used, estimating costs, sorting estimated values and estimating hit values; the device of data indexing based on the full cost calculation is characterized by comprising an index detection module, an index number judgement module, a cost estimation module, an estimation sorting module and a hit number estimation module; a terminal system comprises a processor and a memory device. The method and system of data indexing based on the full cost calculation are capable of achieving cost assessment of the indexes contained in the query conditions each time when performing a query operation, capable of selecting the condition with the least operating cost as the index for the next query, and can effectively improve the efficiency of retrieval.

Description

technical field [0001] The invention relates to the field of data index application computing, in particular to a data index method and system based on full cost calculation. Background technique [0002] Index performance is the key to database performance improvement. The traditional SQL database architecture design is in the era of expensive memory. In order to reduce the demand for memory, the execution process of SQL statements is as follows: [0003] Check grammar for spelling mistakes; [0004] Check whether the access object has corresponding permissions; [0005] Use the internal hash algorithm to obtain the hash value of the SQL, and then compare it with the hash value in the cache; [0006] If there is the same hash value, the execution plan in the cache is directly executed, which is called soft resolution; [0007] If it does not exist, parse the SQL to generate a parsing tree and an execution plan, which is called hard parsing; [0008] Return the execution...

AI Technical Summary

Problems solved by technology

Obviously this is not the optimal execution plan

[0011] In addition, the existing cost calculation method does not take into account the situation that an index contains multiple conditions

[0012] (1) "AND" connection, most of the existing methods choose one of them for cost evaluation: the same index contains condition 1 and condition 2, condition 1 points to 1 million data, condition 2 points to 200 data, select Whether condition 1 or condition 2 seriously affects the cost evaluation of this index;

[0013] (2) "OR" connection, most of the existing methods are direct full table traversal, and the retrieval efficiency is very low

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