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 relation schema is the logical definition of a table-it defines what the name of the table is, and what the name and type of each column is. It's like a plan or a blueprint. A database schema is the collection of relation schemas for a whole database.A table is a structure with a bunch of rows (aka tuples), each of which has the attributes defined by the schema. Tables might also have indexes on them to aid in looking up values on certain columns.A database is, formally, any collection of data.chema Objects. A schema is a collection of logical structures of data, or schema objects. A schema is owned by a database user and has the same name as that user. Each user owns a single schema.