Has works faster than contains, startswith, or endswith. "North America" has_any("south", "north")įor better performance, when there are two operators that do the same task, use the case-sensitive one.įor faster results, if you're testing for the presence of a symbol or alphanumeric word that is bound by non-alphanumeric characters, or the start or end of a field, use has or in. Same as has but works on any of the elements "North and South America" has_all("south", "north") Same as has but works on all of the elements Right-hand-side (RHS) is a whole term in left-hand-side (LHS) For non-ASCII comparison, use the tolower() function. Scanning is much slower than looking up the term in the term index.Ĭase-insensitive operators are currently supported only for ASCII-text. If the query looks for a term that is smaller than three characters, or uses a contains operator, then the query will revert to scanning the values in the column. Kusto builds a term index consisting of all terms that are three characters or more, and this index is used by string operators such as has, !has, and so on. What is a term?īy default, each string value is broken into maximal sequences of ASCII alphanumeric characters, and each of those sequences is made into a term.įor example, in the following string, the terms are Kusto, KustoExplorerQueryRun, and the following substrings: ad67d136, c1db, 4f9f, 88ef, d94f3b6b0b5a. Instead of doing a "plain" substring match, these operators match terms. The semantics of these operators are dictated by the way the column is encoded. These indexes aren't directly exposed, but are used in queries with the string operators that have has as part of their name, such as has, !has, hasprefix, !hasprefix. Multiple indexes are built for such columns, depending on the actual data. Kusto indexes all columns, including columns of type string. The following article describes how string terms are indexed, lists the string query operators, and gives tips for optimizing performance. It will remove the letters that are not necessary and is case insensitive.Kusto offers various query operators for searching string data types.
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