首先需要知道的是redshift不支持SQL语法直接修改varchar(60) 到varchar(90)，但PostgreSQL和MySQL都支持。
1.PostgreSQL如何修改varchar(60)到varchar(90)?
Syntax:
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]
action [, ... ]
where action is one of:
ALTER [ COLUMN ] column_name [ SET DATA ] TYPE data_type [ COLLATE collation ] [ USING expression ]
eg：
postgres=# create table t1(c1 int,c2 varchar(60));
postgres=# insert into t1 values(1,'aaa'),(2,'bbb');
postgres=# alter table t1 alter c2 type varchar(90);
postgres=# \d t1;
Table "public.t1"
Column | Type | Modifiers
--------+-----------------------+-----------
c1 | integer |
c2 | character varying(90) |
2.MySQL如何修改varchar(60)到varchar(90)?
Syntax:
ALTER [IGNORE] TABLE tbl_name
[alter_specification [, alter_specification] ...]
[partition_options]
MODIFY [COLUMN] col_name column_definition
[FIRST | AFTER col_name]
eg:
root@localhost [testdb]>create table t1(c1 int,c2 varchar(60));
root@localhost [testdb]>insert into t1 values(1,'aaa'),(2,'bbb');
root@localhost [testdb]>alter table t1 modify c2 varchar(90);
root@localhost [testdb]>desc t1;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| c1 | int(11) | YES | | NULL | |
| c2 | varchar(90) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
3.redshift如何修改varchar(60)到varchar(90)???
Steps：
(1)Acquire table DDL statement:
pg_dump -h dpp.cmergb1wezbs.us-west-2.redshift.amazonaws.com -U tnadmin -d analytics -p 5439 -s -t facts.auto_events >> auto_events.sql
(2)Create tmp table:
CREATE TABLE facts.auto_events_tmp (
event_name character varying(30),
date_id integer,
log_id character varying(60),
reg_vid character varying(50),
visitor_id character varying(60),
carrier character varying(64),
app_id character varying(60),
entity_id character varying(300),
utc_timestamp timestamp without time zone,
time_zone character varying(60),
ad_id character varying(60),
os_version character varying(20),
connection_type character varying(10),
device_make character varying(20),
device_model character varying(50),
gps_state character varying(10),
map_source character varying(10),
current_lat numeric(15,6),
current_lon numeric(15,6),
altitude numeric(15,6),
horizontal_accuracy numeric(15,6),
vertical_accuracy numeric(15,6),
nav_timestamp timestamp without time zone,
speed numeric(15,6),
assumed_speed numeric(15,6),
traffic_speed numeric(15,6),
heading character varying(50),
edge_id character varying(20),
trigger character varying(30),
type character varying(50),
display_screen character varying(50),
vendor character varying(20),
incident_vendor character varying(20),
flow_vendor character varying(20),
origin_lat numeric(15,6),
origin_lon numeric(15,6),
dest_lat numeric(15,6),
dest_lon numeric(15,6),
impression_id character varying(200),
autosuggest_iid character varying(200),
"position" smallint,
distance numeric(20,4),
duration numeric(20,4),
incident_count integer,
dest_type character varying(20),
route_id character varying(60),
search_id character varying(60),
nav_id character varying(60),
start_engine_id character varying(60),
parent_search_id character varying(60),
parent_route_id character varying(60),
parent_log_id character varying(60),
autosuggest_id character varying(60),
transaction_id character varying(60),
term character varying(200),
status character varying(20),
description character varying(400),
display_option character varying(5),
category_id character varying(20),
category character varying(100),
subcategory character varying(20),
is_sponsored boolean,
notes character varying(400),
old_entity_id character varying(50),
number_of_items integer,
region character varying(20),
home_to_work boolean,
home_to_work_alert character varying(20),
work_to_home boolean,
work_to_home_alert character varying(20),
traffic_setting boolean,
camera_setting boolean,
satellite_setting boolean,
action character varying(20),
zoom_level numeric(20,4),
centroid_lat numeric(15,6),
centroid_lon numeric(15,6),
card_size character varying(10),
language character varying(20),
units character varying(10),
map_color character varying(10),
map_style character varying(5),
lane_assist boolean,
backlight character varying(15),
avoid_highway boolean,
avoid_tolls boolean,
avoid_ferries boolean,
avoid_carpool_lanes boolean,
voice_directions boolean,
voice_traffic boolean,
visual_speed_alert boolean,
audio_speed_alert boolean,
speed_trap boolean,
gas_grade character varying(10),
location_reporting boolean,
speed_limit boolean,
slogtime timestamp without time zone,
mode character varying(30),
sort_type character varying(30),
label character varying(50),
auto_reroute boolean,
avoid_country_borders boolean,
avoid_tunnels boolean,
avoid_unpaved_roads boolean,
predictive_nav_setting boolean,
mercator_coord_x character varying(30),
mercator_coord_y character varying(30),
manufacturer_id character varying(50),
car_id character varying(100),
current_city character varying(50),
current_state character varying(50),
current_country character varying(50),
logshed_app_id character varying(30),
source character varying(20),
response_time bigint,
sdcard_cid character varying(50),
time_left smallint,
vin_hash character varying(100),
model_year character varying(50),
vehicle_manufacturer character varying(2),
car_model character varying(5),
card_id character varying(60),
destination_id character varying(90),
confidence numeric(5,2),
app_version character varying(50),
device_id character varying(50),
caused_by character varying(30),
connected_svcs_product_type integer,
connected_svcs_purchase_state integer,
demo_mode_vehicle_state boolean,
wordsuggest_id character varying(60),
wordsuggest_list character varying(250),
wordsuggest_selected_word character varying(50),
wordsuggest_selected_index smallint,
heading_angle smallint,
request_id character varying(100),
score numeric(5,2),
trigger_cause character varying(300),
base_transaction_tag character varying(100),
change_set character varying(250),
count integer,
db_content character varying(250),
error_id character varying(100),
guid character varying(100),
layer character varying(60),
max_lat numeric(15,6),
min_lat numeric(15,6),
max_lon numeric(15,6),
min_lon numeric(15,6),
size integer,
space_count integer,
space_id character varying(100),
space_string character varying(250),
state character varying(20),
summary_id character varying(100),
transaction_tag character varying(100),
space character varying(250),
feedback_list character varying(5000),
feedback character varying(500),
method character varying(30),
alert_congestion character varying(20),
alert_road_safety character varying(20),
alert_traffic_camera character varying(20),
recommended_speed numeric(15,6),
recommended_assumed_speed numeric(15,6),
recommended_traffic_speed numeric(15,6),
recommended_edge_id character varying(20),
recommended_distance numeric(20,4),
recommended_mercator_coord_x character varying(30),
recommended_mercator_coord_y character varying(30)
);
(3)import data from facts.auto_events to facts.auto_events_tmp
analytics=# select now();
now
-------------------------------
2017-10-12 06:10:37.725145+00
analytics=# select count(*) from facts.auto_events;
count
-----------
336840241
insert into facts.auto_events_tmp select
event_name,
date_id,
log_id,
reg_vid,
visitor_id,
carrier,
app_id,
entity_id,
utc_timestamp,
time_zone,
ad_id,
os_version,
connection_type,
device_make,
device_model,
gps_state,
map_source,
current_lat,
current_lon,
altitude,
horizontal_accuracy,
vertical_accuracy,
nav_timestamp,
speed,
assumed_speed,
traffic_speed,
heading,
edge_id,
trigger,
type,
display_screen,
vendor,
incident_vendor,
flow_vendor,
origin_lat,
origin_lon,
dest_lat,
dest_lon,
impression_id,
autosuggest_iid,
position,
distance,
duration,
incident_count,
dest_type,
route_id,
search_id,
nav_id,
start_engine_id,
parent_search_id,
parent_route_id,
parent_log_id,
autosuggest_id,
transaction_id,
term,
status,
description,
display_option,
category_id,
category,
subcategory,
is_sponsored,
notes,
old_entity_id,
number_of_items,
region,
home_to_work,
home_to_work_alert,
work_to_home,
work_to_home_alert,
traffic_setting,
camera_setting,
satellite_setting,
action,
zoom_level,
centroid_lat,
centroid_lon,
card_size,
language,
units,
map_color,
map_style,
lane_assist,
backlight,
avoid_highway,
avoid_tolls,
avoid_ferries,
avoid_carpool_lanes,
voice_directions,
voice_traffic,
visual_speed_alert,
audio_speed_alert,
speed_trap,
gas_grade,
location_reporting,
speed_limit,
slogtime,
mode,
sort_type,
label,
auto_reroute,
avoid_country_borders,
avoid_tunnels,
avoid_unpaved_roads,
predictive_nav_setting,
mercator_coord_x,
mercator_coord_y,
manufacturer_id,
car_id,
current_city,
current_state,
current_country,
logshed_app_id,
source,
response_time,
sdcard_cid,
time_left,
vin_hash,
vehicle_manufacturer,
car_model,
card_id,
destination_id,
confidence,
app_version,
device_id,
caused_by,
connected_svcs_product_type,
connected_svcs_purchase_state,
demo_mode_vehicle_state,
wordsuggest_id,
wordsuggest_list,
wordsuggest_selected_word,
wordsuggest_selected_index,
heading_angle,
request_id,
score,
trigger_cause,
base_transaction_tag,
change_set,
count,
db_content,
error_id,
guid,
layer,
max_lat,
min_lat,
min_lon,
max_lon,
size,
space_count,
space_id,
space_string,
state,
summary_id,
transaction_tag,
feedback_list,
feedback,
model_year,
space,
method,
alert_congestion,
alert_road_safety,
alert_traffic_camera,
recommended_speed,
recommended_assumed_speed,
recommended_traffic_speed,
recommended_edge_id,
recommended_distance,
recommended_mercator_coord_x,
recommended_mercator_coord_y
from facts.auto_events;
......
INSERT 0 336840241
analytics=# select now();
now
-------------------------------
2017-10-12 06:47:48.722736+00
analytics=# select count(*) from facts.auto_events;
count
-----------
336840241
(4)Modify name:
ALTER TABLE facts.auto_events RENAME TO auto_events_bak_20171012;
ALTER TABLE facts.auto_events_tmp RENAME TO auto_events;
(5)Grant:
ALTER TABLE auto_events OWNER TO tnadmin;
REVOKE ALL ON TABLE auto_events FROM PUBLIC;
REVOKE ALL ON TABLE auto_events FROM tnadmin;
GRANT ALL ON TABLE auto_events TO tnadmin;
GRANT ALL ON TABLE auto_events TO GROUP ops;
GRANT SELECT ON TABLE auto_events TO GROUP restricted;
GRANT SELECT,INSERT,REFERENCES,DELETE,UPDATE ON TABLE auto_events TO client_events_etl_user;
GRANT SELECT ON TABLE auto_events TO cristianap;
GRANT SELECT ON TABLE auto_events TO PUBLIC;
GRANT SELECT ON TABLE auto_events TO yanhuiw;
GRANT SELECT ON TABLE auto_events TO yujiew;
analytics=# \dp facts.auto_events;
Access privileges
schema | name | type | access privileges
--------+-------------+-------+--------------------------------------
facts | auto_events | table | tnadmin=arwdRxt/tnadmin +
| | | group ops=arwdRxt/tnadmin +
| | | group restricted=r/tnadmin +
| | | client_events_etl_user=arwdx/tnadmin+
| | | cristianap=r/tnadmin +
| | | =r/tnadmin +
| | | yanhuiw=r/tnadmin +
| | | yujiew=r/tnadmin
PS:有两个对表字段较多情况下的处理方法：
awk '{print $1}' temp.txt|sed 's#$#,#g'
awk -F "|" '{print $1,$2}' temp.txt|sed 's#$#,#g'
