DATA_READS

Lists each storage location that a query reads in Eon Mode.

Eon Mode only

Lists each storage location that a query reads in Eon Mode. If the query fetches data from multiple locations, this table provides a row for each location per node that read data. For example, a query might run on three nodes and fetch data from the depot and communal storage. In this case, the table displays six rows for the query: three rows for each node's depot read, and three for each node's communal storage read.

Column Name Column Type Description
START_TIME TIMESTAMP When Vertica started reading data from the location.
NODE_NAME VARCHAR Name of the node that fetched the data
SESSION_ID VARCHAR Unique numeric ID assigned by the Vertica catalog, which identifies the session for which profiling information is captured. This identifier is unique within the cluster at any point in time but can be reused when the session closes.
USER_ID INT Unique numeric ID assigned by the Vertica catalog, which identifies the user.
USER_NAME VARCHAR Name of the user running the query.
TRANSACTION_ID INT Identifier for the transaction within the session, if any. If a session is active but no transaction has begun, TRANSACTION_ID returns NULL.
STATEMENT_ID INT Unique numeric ID for the statement that Set Snippet Variable Value in Topic. NULL indicates that no statement is currently being processed. The combination of TRANSACTION_ID and STATEMENT_ID uniquely identifies a statement within a session; these columns are useful for creating joins with other system tables.
REQUEST_ID INT ID of the data request.
LOCATION_ID INT ID of the storage location read.
LOCATION_PATH VARCHAR Path of the storage container read by the query.
BYTES_READ INT Number of bytes read by the query from this location.

Examples

=> SELECT * FROM V_MONITOR.DATA_READS WHERE TRANSACTION_ID = 45035996273707457;
-[ RECORD 1 ]--+---------------------------------------------------
start_time     | 2019-02-13 19:43:43.840836+00
node_name      | v_verticadb_node0001
session_id     | v_verticadb_node0001-11828:0x6f3
user_id        | 45035996273704962
user_name      | dbadmin
transaction_id | 45035996273707457
statement_id   | 1
request_id     | 230
location_id    | 45035996273835000
location_path  | /vertica/data/verticadb/v_verticadb_node0001_depot
bytes_read     | 329460142
-[ RECORD 2 ]--+---------------------------------------------------
start_time     | 2019-02-13 19:43:43.8421+00
node_name      | v_verticadb_node0002
session_id     | v_verticadb_node0001-11828:0x6f3
user_id        | 45035996273704962
user_name      | dbadmin
transaction_id | 45035996273707457
statement_id   | 1
request_id     | 0
location_id    | 45035996273835002
location_path  | /vertica/data/verticadb/v_verticadb_node0002_depot
bytes_read     | 329473033
-[ RECORD 3 ]--+---------------------------------------------------
start_time     | 2019-02-13 19:43:43.841845+00
node_name      | v_verticadb_node0003
session_id     | v_verticadb_node0001-11828:0x6f3
user_id        | 45035996273704962
user_name      | dbadmin
transaction_id | 45035996273707457
statement_id   | 1
request_id     | 0
location_id    | 45035996273835004
location_path  | /vertica/data/verticadb/v_verticadb_node0003_depot
bytes_read     | 329677294