27 real Data Types questions from the SQL bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is BIGINT?
Junior
A.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
B.a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones
C.an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
D.an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
A.BIGINT — a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
B.BIGINT — an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
C.BIGINT — a fixed-length character type that pads stored strings with trailing spaces up to the declared width
D.BIGINT — a 128-bit universally unique identifier often used as a key that can be generated on the client without coordinating with the database
A.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
B.a fixed-length character type that pads stored strings with trailing spaces up to the declared width
C.an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
D.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
A.CHAR — a fixed-length character type that pads stored strings with trailing spaces up to the declared width
B.CHAR — a type holding the logical values true or false (and possibly unknown via NULL)
C.CHAR — an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
D.CHAR — a variable-length character type that stores only the actual characters supplied, up to a declared maximum length
A.an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
B.a variable-length character type that stores only the actual characters supplied, up to a declared maximum length
C.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
D.a type holding the logical values true or false (and possibly unknown via NULL)
A.VARCHAR — a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
B.VARCHAR — a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones
C.VARCHAR — a variable-length character type that stores only the actual characters supplied, up to a declared maximum length
D.VARCHAR — an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
11. Which term means: "an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point"?
A.DECIMAL — an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
B.DECIMAL — a variable-length character type that stores only the actual characters supplied, up to a declared maximum length
C.DECIMAL — an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
D.DECIMAL — a 128-bit universally unique identifier often used as a key that can be generated on the client without coordinating with the database
A.a type holding the logical values true or false (and possibly unknown via NULL)
B.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
C.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
D.an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
14. Which term means: "an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values"?
A.FLOAT — an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
B.FLOAT — an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
C.FLOAT — an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
D.FLOAT — a type holding the logical values true or false (and possibly unknown via NULL)
A.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
B.a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones
C.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
D.an 8-byte signed integer type used when values may exceed the roughly two-billion limit of an ordinary 4-byte integer
17. Which term means: "a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones"?
A.TIMESTAMPTZ — a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
B.TIMESTAMPTZ — an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
C.TIMESTAMPTZ — a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones
D.TIMESTAMPTZ — a fixed-length character type that pads stored strings with trailing spaces up to the declared width
A.an exact fixed-precision numeric type (also called NUMERIC) preferred for money because it avoids the rounding errors of binary floating point
B.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
C.a 128-bit universally unique identifier often used as a key that can be generated on the client without coordinating with the database
D.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
20. Which term means: "a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting"?
A.JSONB — a 128-bit universally unique identifier often used as a key that can be generated on the client without coordinating with the database
B.JSONB — a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
C.JSONB — an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
D.JSONB — a type holding the logical values true or false (and possibly unknown via NULL)
23. Which term means: "a 128-bit universally unique identifier often used as a key that can be generated on the client without coordinating with the database"?
A.a point-in-time type that stores an instant in UTC and converts to the session time zone, unlike a plain timestamp that ignores zones
B.a type holding the logical values true or false (and possibly unknown via NULL)
C.an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
D.a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
A.BOOLEAN — a Postgres binary-encoded document type that supports indexing and fast key access, trading slightly slower writes versus the plain text JSON type which preserves formatting
B.BOOLEAN — a type holding the logical values true or false (and possibly unknown via NULL)
C.BOOLEAN — a fixed-length character type that pads stored strings with trailing spaces up to the declared width
D.BOOLEAN — an approximate binary floating-point numeric type that can introduce small rounding errors and is unsuitable for exact monetary values
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