event 
Logical Entity Name  event 
Default Table Name  event 
Definition  Summary information on an event 

event Attributes 
Attribute/Logical Rolename  Domain  Datatype  NULL  Definition 
evid(PK)    NUMERIC(15, 0)  NO  Event identifier. Each event is assigned a unique integer which identifies it in a database. It is possible for several records in the Origin relation to have the same evid. This indicates there are several opinions about the location of the event. The evid does not have to be identical to the local network’s event identifier, which is stored in the Origin table. This allows merging data for a single event from multiple sources without insisting that database evid is identical to the source’s local event identifier 
prefor(FK)    NUMERIC(15, 0)  YES  Preferred origin. This attribute holds the origin identifier, orid, that points to the preferred origin for a seismic event 
prefmag(FK)    NUMERIC(15, 0)  YES  Preferred magnitude. This attribute holds the magnitude identifier, magid, that points to the preferred magnitude for a seismic event or an origin 
prefmec(FK)    NUMERIC(15, 0)  YES  Preferred mechanism. This attribute holds the mechanism identifier, mecid, that points to the preferred mechanism for a seismic event or an origin 
commid    NUMERIC(15, 0)  YES  Comment identification. This is a key used to point to free-form comments entered in the Remark relation. These comments store additional information about a tuple in another relation. Within the Remark relation, there may be many tuples with the same commid and different lineno, but the same commid will appear in only one other tuple among the rest of the relations in the database 
auth    VARCHAR(15)  NO  The auth field specifies the source of the information. This may be a network identifier (FDSN or otherwise), or any other string indicating the source of the information in the record 
subsource    VARCHAR(8)  YES  A second identifier to specify the system or process that derived the data. e.g., the origin's AUTH is CI, but the subsource (the solution) was computed by JIGGLE 
etype    VARCHAR(7)  YES  This attribute is used to identify the type of seismic event, when known 
selectflag    NUMERIC(1, 0)  YES  This flag describes the “definitive” definition of an event. Helps to differentiate which event to use from two different real-time systems 
lddate    DATE  YES  Load date. Date and time that the record was created or last modified, in Oracle date datatype 
version    NUMERIC(3, 0)  YES  Event version number. This attribute is incremented each time the preferred origin, magnitude or mechanism of the event is updated 

event Relationships 
Parent Entity  Child Entity  Type  Foreign Keys 
mec  event  Non-Identifying  prefmec 
netmag  event  Non-Identifying  prefmag 
origin  event  Non-Identifying  prefor 
remark  event  Non-Specific   
event  eventprefmag  Non-Identifying  evid 
event  origin  Non-Identifying  evid 
event  significant_event  Identifying  evid 

event Check Constraints 
Check Constraint Name  CheckConstraint 
event01  etype in ('le','re','ts','qb','nt', 'ca','sn','uk','st') 
event02  evid > 0