14. The method of claim 1 , further comprising: detecting, by the database management system, a second hint in a fourth query, wherein the fourth query has a fourth signature; determining, by the database management system, that the second signature correlates with the fourth signature; determining, by evaluating a set of hint data which indicates relevancy of both the hint in the first query and the second hint in the fourth query, to use the hint in the first query; calculating a first proportion of a table of the database management system which is selected when processing the first query; calculating a second proportion of the table of the database management system which is selected when processing the second query; determining the second proportion is within a mathematical threshold of the first proportion; computing a first index for the first query; computing a second index for the second query; and determining an index similarity relationship with respect to the second index and the first index.
14. The method of claim 1 , further comprising: detecting, by the database management system, a second hint in a fourth query, wherein the fourth query has a fourth signature; determining, by the database management system, that the second signature correlates with the fourth signature; determining, by evaluating a set of hint data which indicates relevancy of both the hint in the first query and the second hint in the fourth query, to use the hint in the first query; calculating a first proportion of a table of the database management system which is selected when processing the first query; calculating a second proportion of the table of the database management system which is selected when processing the second query; determining the second proportion is within a mathematical threshold of the first proportion; computing a first index for the first query; computing a second index for the second query; and determining an index similarity relationship with respect to the second index and the first index. 15. The method of claim 14 , wherein: the first and second signatures are based on a first group consisting of at least one of: a parsed Structured Query Language (SQL) statement, an SQL tokenization, a token tree comparison, a table analysis, or a column bitmap; the hint includes a selection from a second group consisting of at least one of: a table scan, an index choice, an index implementation, a join order, a join implementation, a statistic, a grouping implementation, an ordering implementation, a database code level, an optimization goal, a fair memory share, live data, a processing intensive goal, a parameter marker implementation, or a materialization goal; relevancy is related to a set of index costs; the set of index costs includes a second index cost for the second query and a query plan index cost for the query plan; and the query plan index cost exceeds the second index cost.