Search results
Results from the WOW.Com Content Network
With the same table, the query SELECT * FROM T WHERE C1 = 1 will result in all the elements of all the rows where the value of column C1 is '1' being shown – in relational algebra terms, a selection will be performed, because of the WHERE clause. This is also known as a Horizontal Partition, restricting rows output by a query according to ...
This makes them efficient, but limits them to particular vendors. So far PostgreSQL is the only vendor to have announced a live product with this specific feature, in PostgreSQL 9.5. [ 3 ] [ 4 ] Other vendors have described some similar features, [ 2 ] including Oracle , [ 5 ] [ 6 ] Netezza 'zone maps', [ 7 ] Infobright 'data packs', [ 8 ...
|-adds a new row, which should be followed by the same number of cells found in other rows. Note, rowspan="2" and colspan="2" can be used on cells to span multiple rows and columns. Header cells are created with ! Header cell, which can be column or row headers. Data cells are created with | Data cell. A new column can be added by adding ...
Max row size Max columns per row Max Blob/Clob size Max CHAR size Max NUMBER size Min DATE value Max DATE value Max column name size Informix Dynamic Server: ≈0.5 YB 12: ≈0,5YB 12: 32,765 bytes (exclusive of large objects) 32,765 4 TB 32,765 14: 10 125 13: 01/01/0001 10: 12/31/9999 128 bytes Ingres: Unlimited Unlimited 256 KB 1,024 2 GB 32 ...
Each row in a table has its own unique key. Rows in a table can be linked to rows in other tables by adding a column for the unique key of the linked row (such columns are known as foreign keys). Codd showed that data relationships of arbitrary complexity can be represented by a simple set of concepts. [2]
In situations where the number of unique values of a column is far less than the number of rows in the table, column-oriented storage allow significant savings in space through data compression. Columnar storage also allows fast execution of range queries (e.g., show all records where a particular column is between X and Y, or less than X.)
The answer is that when the table has a row without containing any rowspan=1 cell, this row is "compressed" upwards and disappears. Solution: divide one of the tall cells so that the row gets one rowspan=1 cell (and don't mind the eventual loss of text-centering). Then kill the border between them.
Row labels are used to apply a filter to one or more rows that have to be shown in the pivot table. For instance, if the "Salesperson" field is dragged on this area then the other output table constructed will have values from the column "Salesperson", i.e., one will have a number of rows equal to the number of "Sales Person". There will also ...