![]() Or: how to compare chars from different languages? How to compare Cyrillic "T" to latin "T"? In UTF/Unicode such comparison is possible (and Vertica data encoded in UTF-8). FYI: For UTF/Unicode its a big problem/challenge - case sensitive comparison, because same letters in different languages can has different order. There are two main differences between the two: ILIKE is case-insensitive whereas LIKE is case-sensitive. You can use these SQL commands via phpMyAdmin on our Cloudways Alternative hosting plans. In a parameter query, you can prompt the user for a pattern to search for. For example, if you enter Like 'C' in an SQL query, the query returns all field values beginning with the letter C. ![]() To avoid searching the web for sample data I decided to generate some data. In an expression, you can use the Like operator to compare a field value to a string expression. Before we get started I have created some sample data. The first query, using LIKE, will be unable to use an index, since it starts with a wildcard, so will always require a full table scan. These index types are not equally efficient, so it makes sense to dig into the subject matter and figure out what is best when. LIKE is case sensitive, ILIKE is case insensitive. Both index type can handle LIKE as well as ILIKE. I don't know what strategy Vertica choose, both strategies has same complexity in worst case => O(length of string). Published on Maby Kevin Graham The predicates LIKE and ILIKE are used to search for strings that match a given pattern, so you can search or for a single word (or string) in a long text field. Can be another strategy: convert all strings to same case (lower or upper) and prepare case-sensitive comparison. test=> select ascii('a'), ascii('A'), 'a' > 'A' ascii | ascii | ?column? -+-+- 97 | 65 | t (1 row) So non-case sensitive search require 2 comparison for decision: character compared to "small" AND "capital" letter. ![]() ![]() Unlike the LIKE function, string matching is case-insensitive. The LIKE and ILIKE statements are functionally equivalent except for one important difference: the LIKE statement is case-sensitive while the ILIKE statement is. For example ASCII table comparison: small "a" = 97, while capital "A" = 65. Allows matching of strings based on comparison with a pattern. Hi! Case-sensitive search ALWAYS will be faster than non sensitive, because it compares chars by their order in characters table. ![]()
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