to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.16.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.16.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.16.2. COALESCE COALESCE(value [, ...]) The COALESCE function

to simplify the constant subex- pression, even if every row in the table has x > 0 so that the ELSE arm would never be entered at run time. While that particular example might seem silly, related cases three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance subexpression will usually result in a division-by-zero failure at planning time, even if it’s within a CASE arm that would never be entered at run time. 9.16.2. COALESCE COALESCE(value [, ...]) The COALESCE function

equivalent to a < x OR a > y There is no difference between the two respective forms apart from the CPU cycles required to rewrite the first one into the second one internally. To check whether a value (in bytes) of rows output by this plan node The costs are measured in units of disk page fetches. (CPU effort estimates are converted into disk-page units using some fairly arbitrary fudge factors. If you is estimated at 233 page reads, defined as costing 1.0 apiece, plus 10000 * cpu_tuple_cost which is currently 0.01 (try SHOW cpu_tuple_cost). Now let’s modify the query to add a WHERE condition: EXPLAIN

equivalent to a < x OR a > y There is no difference between the two respective forms apart from the CPU cycles required to rewrite the first one into the second one internally. BETWEEN SYMMETRIC is the same in units of disk page fetches; that is, 1.0 equals one sequential disk page read, by definition. (CPU effort estimates are made too; they are converted into disk-page units using some fairly arbitrary is estimated at 358 page reads, defined as costing 1.0 apiece, plus 10000 * cpu_tuple_cost which is typically 0.01 (try SHOW cpu_tuple_cost). Now let’s modify the query to add a WHERE condition: EXPLAIN