Currently adding a column to a table with a non-NULL default results in
a rewrite of the table. For large tables this can be both expensive and
disruptive. This patch removes the need for the rewrite as long as the
default value is not volatile. The default expression is evaluated at
the time of the ALTER TABLE and the result stored in a new column
(attmissingval) in pg_attribute, and a new column (atthasmissing) is set
to true. Any existing row when fetched will be supplied with the
attmissingval. New rows will have the supplied value or the default and
so will never need the attmissingval.
xs (phones), sm (tablets), md (desktops), and lg (larger desktops).
Each tier of classes scales up, meaning if you plan on setting the same widths for xs and sm, you only need to specify xs.
Column, index, and stored routine names are not case sensitive on any platform, nor are column aliases. Trigger names are case sensitive, which differs from standard SQL.
Cargo cult software engineering is easy to identify. Cargo cult software engineers justify their practices by saying, "We’ve always done it this way in the past," or "our company standards require us to do it this way"—even when those ways make no sense.
Describe Cassandra data model with examples and simplicity. This tutorial includes column, super column, column family, super column family, keyspace, validator & comparator.
Industry Analyst Don Feinberg & Vertica CTO Mike Stonebraker on Analytic Databases "COLUMN DATABASES typically outperform all other databases including those that are built specifically for data warehousing," Feinberg says. Watch this podcast to learn how
S. Harizopoulos, V. Liang, D. Abadi, and S. Madden. VLDB '06: Proceedings of the 32nd international conference on Very large data bases, page 487--498. VLDB Endowment, (2006)
D. Abadi, S. Madden, and M. Ferreira. SIGMOD '06: Proceedings of the 2006 ACM SIGMOD international conference on Management of data, page 671--682. New York, NY, USA, ACM, (2006)