During the menstrual cycle, an egg is released from one of the womanâs ovaries and travels down the fallopian tube. The egg only lives for 24 hours after ovulation, and a sperm must meet the egg within that period for pregnancy to happen.uring the menstrual cycle, an egg is released from one of the womanâs ovaries and travels down the fallopian tube. The egg only lives for 24 hours after ovulation, and a sperm must meet the egg within that period for pregnancy to happen.
A set of attributes is called a relation schema (or relation scheme). A relation schema is also known as table schema (or table scheme).A relation schema can be thought of as the basic information describing a table or relation. It is the logical definition of a table.Relation schema defines what the name of the table is. This includes a set of column names, the data types associated with each column. set of attributes is called a relation schema (or relation scheme). A relation schema is also known as table schema (or table scheme).
A set of related columns is usually called a row, and a table is a collection of rows. As for database structures, every table has a definition, which includes stuff like the table's name, its columns, its keys and indexes, etc. This can be called the table's structure or table's schema. A database structure, or more formally a database schema, is the set of table schemas, as well as other objects such as stored procedures, triggers, security and access definitions, etc that make up the db world for a particular db application.