Re: BUG #14150: Attempted to delete invisible tuple

I have also experienced this bug while using upserts.  I've been able to
reproduce it with a significantly simpler table/upsert than virenda's
example.

````
CREATE TABLE IF NOT EXISTS cache (
    id SERIAL,
    key TEXT PRIMARY KEY NOT NULL CHECK (octet_length(key) < 256),
    value JSON CHECK (octet_length(value::text) < 10 * 1024 * 1024),
    expires_at TIMESTAMP NOT NULL
);
CREATE INDEX cache_expires_at_idx ON cache USING btree (expires_at);
````

From my logs:
````
2016-06-08 00:54:18 UTC:10.10.4.142(59691):user@dbname:[13169]:ERROR:
attempted to delete invisible tuple
2016-06-08 00:54:18 UTC:10.10.4.142(59691):user@dbname:[13169]:STATEMENT:
INSERT INTO cache (key, value, expires_at) VALUES ($1, $2, $3) ON CONFLICT
(key) DO UPDATE SET value=EXCLUDED.value, expires_at=EXCLUDED.expires_at
````

This was a freshly provisioned postgreSQL 9.5.2 on RDS with no imported
data.  The issue appeared less than a minute after stress testing it with
insert/updates.  I don't yet have a working test case, but I've only seen
it when there's quite a bit of concurrency.

-Peter

------------------------

> From:   virendra(at)idyllic-software(dot)com
> To: pgsql-bugs(at)postgresql(dot)org
> Subject:    BUG #14150: Attempted to delete invisible tuple
> Date:   2016-05-19 12:33:38
> Message-ID: 20160519123338.12513.20271@wrigleys.postgresql.org
> Thread: 2016-05-19 12:33:38 from virendra(at)idyllic-software(dot)com
>
> The following bug has been logged on the website:
>
> Bug reference:      14150
> Logged by:          Viren Negi
> Email address:      virendra(at)idyllic-software(dot)com
> PostgreSQL version: 9.5.2
> Operating system:   Mac OS
> Description:
>
> ## We have system where we perform lot of insert and update (no delete)
and
> some time upsert query.
>
> ## Error the ruby pg library report
>    PG::ObjectNotInPrerequisiteState: ERROR:  attempted to delete invisible
> tuple
>
> ## Schema for call_records
> psql
> database=# \d call_records;
>                                           Table "public.call_records"
>        Column        |            Type             |

> Modifiers
>
---------------------+-----------------------------+-----------------------------------------------------------
>  id                  | integer                     | not null default
> nextval('call_records_id_seq'::regclass)
>  sequence_number     | character varying           |
>  more_data           | character varying           |
>  acd                 | character varying           |
>  crn                 | character varying           |
>  efd                 | integer                     | default 0
>  ror                 | character varying           |
>  slr                 | integer                     |
>  slt                 | integer                     |
>  raw_data            | bytea                       |
>  created_at          | timestamp without time zone | not null
>  updated_at          | timestamp without time zone | not null
>  crn_data            | character varying           |
>  file_detail_id      | integer                     |
>  problems            | hstore                      | not null default
> ''::hstore
>  plain_crn           | bigint                      |
>  parsed_json         | json                        |
>  raw_processing_data | bytea                       |
>  timestamp           | bigint                      | default 0
>  active              | boolean                     | default true
> Indexes:
>     "call_records_pkey" PRIMARY KEY, btree (id)
>     "index_call_records_on_crn" UNIQUE, btree (crn)
>     "index_call_records_on_plain_crn" UNIQUE, btree (plain_crn)
>     "index_call_records_on_file_detail_id" btree (file_detail_id)
> Foreign-key constraints:
>     "fk_rails_f25dc6ba1c" FOREIGN KEY (file_detail_id) REFERENCES
> file_details(id) ON DELETE CASCADE
> Referenced by:
>     TABLE "call_processing_records" CONSTRAINT "fk_rails_2d36d7abd8"
FOREIGN
> KEY (call_record_id) REFERENCES call_records(id) ON DELETE CASCADE
>
> ## For the following insert(upsert) query
>
>
> INSERT INTO
>
call_records(plain_crn,efd,acd,slt,slr,ror,raw_processing_data,parsed_json,timestamp,active,created_at,updated_at)
> VALUES>