What is the effect of specifying the "ENABLE PLUGGABLE DATABASE" clause in a "CREATE DATABASE" statement?

Question

Options

• AIt will create a multitenant container database (CDB) with only the root opened.
• BIt will create a CDB with root opened and seed read only.
• CIt will create a CDB with root and seed opened and one PDB mounted.
• DIt will create a CDB that must be plugged into an existing CDB.
• EIt will create a CDB with root opened and seed mounted.

• A
  5% (1)
• B
  89% (17)
• C
  5% (1)

Explanation

When you include ENABLE PLUGGABLE DATABASE in a CREATE DATABASE statement, Oracle creates a new CDB with two containers in specific states: the root (CDB$ROOT) is opened in READ WRITE mode, and the seed (PDB$SEED) is automatically opened in READ ONLY mode - making B the correct answer. The seed is always read-only by design because it serves as an immutable template for cloning new PDBs; allowing writes to it would corrupt the template.

Why the distractors fail:

• A - The seed is not merely absent; it exists and is opened (read-only), so "only the root" is incomplete.
• C - No additional PDB is created automatically; you must explicitly create PDBs after the CDB exists.
• D - You are creating a standalone CDB, not plugging it into another one; that describes a different operation entirely.
• E - "Mounted" means the control file is read but the database isn't open; the seed is actually opened (just read-only), not merely mounted.

Memory tip: Picture the seed as a "shrink-wrapped template" - it's open so Oracle can read it to stamp out new PDBs, but it's read-only so no one can tamper with the mold. Root = open for business (read-write); Seed = open for viewing only (read-only).

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