Reference - Record and File Locking

🔒 Tutorial

GGP includes record and file locking mechanisms to ensure data integrity and prevent conflicts in network environments. This article outlines the key types of locks and their implementation within GGP.

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🔑 Definitions

Lock Type	Description
Record Read Lock	Someone is viewing the record.
Record Write Lock	Someone is editing the record. Others cannot view, edit, or delete it until the lock is released.
File Read Lock	The overlay is in use (e.g. displayed, queried, or viewed).
File Write Lock	An exclusive process (e.g. re-indexing or integrity check) is running on the overlay. No other access is allowed until it's done.

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⚙️ Locking in Practice

🔁 Record Locks

• Opening an overlay form (e.g. via right-click) initially applies a Read lock to the record.

• Typing in a field (first character only) upgrades this to a Write lock, unless another user already holds a Read or Write lock — in that case, a lock warning will appear.

• [Link to Database] and [Link from Database] buttons also apply a Write lock.

🔄 Navigating Records

• Using [Next], [Previous], or [Next Overlay] removes the current lock (implies Cancel).

• [Save]:

  • If no edits, the record is unlocked immediately.

  • If edits were made, a Save confirmation dialog appears:

    • Yes: Saves and unlocks

    • No: Leaves form open

• [Cancel]:

  • If no edits, record is unlocked.

  • If edits were made, an Abandon Changes dialog appears:

    • Yes: Unlocks

    • No: Keeps form open

🖊️ Graphic Edits

• When editing or deleting geometry, a Write lock is applied as soon as the GGP record confirmation form appears.

• Lock is released upon saving, canceling, or deleting the geometry.

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🧼 Automatic Lock Cleanup

• If GGP, Windows, or the PC crashes:
  When the user logs back in, all their previous locks are cleared automatically.

• Alternatively, an admin can clear a user’s locks manually using [Reset] in the GMAIN32 User module.

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⚠️ Lock Conflicts

• Any lock (read/write, file/record) will prevent operations such as:

  • Zapping

  • Importing

  • Re-indexing

  • Global attribute changes

  • Integrity checks

• Viewing a table (via database or spatial query, or from Search > View Table) sets a file Read lock, which blocks write access until the table form is closed.