Search results
Results From The WOW.Com Content Network
[4]: 114 A DataFrame is a 2-dimensional data structure of rows and columns, similar to a spreadsheet, and analogous to a Python dictionary mapping column names (keys) to Series (values), with each Series sharing an index. [4]: 115 DataFrames can be concatenated together or "merged" on columns or indices in a manner similar to joins in SQL.
A table is an arrangement of columns and rows that organizes and positions data or images. Tables can be created on Wikipedia pages using special wikitext syntax, or HTML syntax, and many different styles and tricks can be used to customise them.
Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records. An index is a copy of selected columns of data, from a table, that is designed to enable very efficient search.
The website was created by Jeff Atwood and Joel Spolsky in 2008. [5] The name for the website was chosen by voting in April 2008 by readers of Coding Horror , Atwood's programming blog. [ 18 ] On 31 July 2008, Jeff Atwood sent out invitations encouraging his subscribers to take part in the private beta of the new website, limiting its use to ...
The Start date/time of the second row is equal to the End date/time (or next) of the previous row. The null End_Date in row two indicates the current tuple version. A standardized surrogate high date (e.g. 9999-12-31) may instead be used as an end date so that null-value substitution is not required when querying.
Discover the latest breaking news in the U.S. and around the world — politics, weather, entertainment, lifestyle, finance, sports and much more.
Pivot tables are not created automatically. For example, in Microsoft Excel one must first select the entire data in the original table and then go to the Insert tab and select "Pivot Table" (or "Pivot Chart"). The user then has the option of either inserting the pivot table into an existing sheet or creating a new sheet to house the pivot table.
The information stored in a self-defining record can be interpreted as metadata for the record, which is similar to what one would expect to find in the UNIX metadata regarding a file, containing information such as the record's creation time and the size of the record in bytes. Alternatively, various elements of the record, each including an ...