On 2017-01-04 06:53:31 -0800, Adrian Klaver wrote: > On 01/04/2017 05:00 AM, vod vos wrote: > >Now I am confused about I can create 1100 columns in a table in > >postgresql, but I can't copy 1100 values into the table. And I really > > As pointed out previously: > > https://www.postgresql.org/about/ > Maximum Columns per Table 250 - 1600 depending on column types > > That being dependent on both the number of columns and the actual data in > the columns. I think this is confusingly phrased. In my mind "column type" is static - the type is the same, independent of the values which are stored. So "250 - 1600 depending on column types" implies to me that there is some type A of which I can have only 250 columns and another type B of which I can have 1600 columns. But it doesn't imply to me that the number of columns depends on the values which ar put into those columns. May I suggest the these improvements? In https://www.postgresql.org/about/: Instead of | 250 - 1600 depending on column types write | 250 - 1600 depending on column types and data In https://www.postgresql.org/docs/9.6/static/ddl-basics.html: Replace the sentence: | Depending on the column types, it is between 250 and 1600. with: | For all columns in a row, some information (either the data itself or | a pointer to the data) must be stored in a single block (8 kB). | Because for some types this data is itself of variable length, the | maximum number of columns depends not only on the types of the columns | but also on the data (e.g., a NULL uses less space than a non-NULL | value). Therefore there is no simple way to compute the maximum number | of columns, and it is possible to declare a table with more columns | than can be filled. Keeping all this in mind, the limit is between 250 | and 1600. hp -- _ | Peter J. Holzer | A coding theorist is someone who doesn't |_|_) | | think Alice is crazy. | | | hjp@xxxxxx | -- John Gordon __/ | http://www.hjp.at/ | http://downlode.org/Etext/alicebob.html
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