pocket table structure

The list of pockets in the model is contained within this table, and identifies the link and direction where the pocket is located as well as its type, which is one of “RIGHT_TURN”, “LEFT_TURN”, “RIGHT_MERGE” or “LEFT_MERGE”. The lane from which the pocket starts from, as well as its length are also part of the table.

Only pockets used in the connections table are included in this table.

Table Structure

Field	Type	NULL allowed	Default Value	Foreign key	Description
pocket*	INTEGER	NO
link	INTEGER	YES		Link(link)	bidirectional link containing the pocket
dir	INTEGER	NO	0		direction (0 for AB or 1 for BA) of the link
type	TEXT	NO	‘’		type (LEFT_TURN, RIGHT_TURN)
lanes	INTEGER	NO	0		number of pocket lanes
length	REAL	YES	0		length (in meters) of the pocket
offset	REAL	YES	0		Not used by POLARIS

(* - Primary key)

The SQL statement for table and index creation is below.

CREATE TABLE IF NOT EXISTS "Pocket" (
    "pocket"    INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    "link"      INTEGER,
    "dir"       INTEGER NOT NULL DEFAULT 0,
    "type"      TEXT    NOT NULL DEFAULT '',
    "lanes"     INTEGER NOT NULL DEFAULT 0,
    "length"    REAL             DEFAULT 0,
    "offset"    REAL             DEFAULT 0,

    CONSTRAINT "link_fk" FOREIGN KEY("link") REFERENCES "Link"("link") DEFERRABLE INITIALLY DEFERRED -- check
);

CREATE UNIQUE INDEX IF NOT EXISTS Pocket_unique ON Pocket (link, "dir", "type");