Запускаю psql:
>>> psql
psql: ?????: ???? ?????? "fx" ?? ??????????
org.postgresql.util.PSQLException: ?????: ???????????? "postgres" ?? ?????? ???????? ??????????? (?? ??????)
>>> locale -a
aa_DJ
aa_DJ.iso88591
aa_DJ.utf8
aa_ER
aa_ER@saaho
aa_ER.utf8
aa_ER.utf8@saaho
aa_ET
aa_ET.utf8
af_ZA
af_ZA.iso88591
af_ZA.utf8
am_ET
am_ET.utf8
an_ES
an_ES.iso885915
an_ES.utf8
ar_AE
ar_AE.iso88596
ar_AE.utf8
ar_BH
ar_BH.iso88596
ar_BH.utf8
ar_DZ
ar_DZ.iso88596
ar_DZ.utf8
ar_EG
ar_EG.iso88596
ar_EG.utf8
ar_IN
ar_IN.utf8
ar_IQ
ar_IQ.iso88596
ar_IQ.utf8
ar_JO
ar_JO.iso88596
ar_JO.utf8
ar_KW
ar_KW.iso88596
ar_KW.utf8
ar_LB
ar_LB.iso88596
ar_LB.utf8
ar_LY
ar_LY.iso88596
ar_LY.utf8
ar_MA
ar_MA.iso88596
ar_MA.utf8
ar_OM
ar_OM.iso88596
ar_OM.utf8
ar_QA
ar_QA.iso88596
ar_QA.utf8
ar_SA
ar_SA.iso88596
ar_SA.utf8
ar_SD
ar_SD.iso88596
ar_SD.utf8
ar_SY
ar_SY.iso88596
ar_SY.utf8
ar_TN
ar_TN.iso88596
ar_TN.utf8
ar_YE
ar_YE.iso88596
ar_YE.utf8
as_IN.utf8
ast_ES
ast_ES.iso885915
ast_ES.utf8
az_AZ.utf8
be_BY
be_BY.cp1251
be_BY@latin
be_BY.utf8
be_BY.utf8@latin
bem_ZM
bem_ZM.utf8
ber_DZ
ber_DZ.utf8
ber_MA
ber_MA.utf8
bg_BG
bg_BG.cp1251
bg_BG.utf8
bn_BD
bn_BD.utf8
bn_IN
bn_IN.utf8
bo_CN
bo_CN.utf8
bo_IN
bo_IN.utf8
br_FR
br_FR@euro
br_FR.iso88591
br_FR.iso885915@euro
br_FR.utf8
bs_BA
bs_BA.iso88592
bs_BA.utf8
byn_ER
byn_ER.utf8
C
ca_AD
ca_AD.iso885915
ca_AD.utf8
ca_ES
ca_ES@euro
ca_ES.iso88591
ca_ES.iso885915@euro
ca_ES.iso885915@valencia
ca_ES.utf8
ca_ES.utf8@valencia
ca_ES@valencia
ca_FR
ca_FR.iso885915
ca_FR.utf8
ca_IT
ca_IT.iso885915
ca_IT.utf8
catalan
crh_UA
crh_UA.utf8
csb_PL
csb_PL.utf8
cs_CZ
cs_CZ.iso88592
cs_CZ.utf8
C.UTF-8
cv_RU
cv_RU.utf8
cy_GB
cy_GB.iso885914
cy_GB.utf8
czech
da_DK
da_DK.iso88591
da_DK.utf8
danish
dansk
de_AT
de_AT@euro
de_AT.iso88591
de_AT.iso885915@euro
de_AT.utf8
de_BE
de_BE@euro
de_BE.iso88591
de_BE.iso885915@euro
de_BE.utf8
de_CH
de_CH.iso88591
de_CH.utf8
de_DE
de_DE.iso88591
de_DE.utf8
deutsch
en_AG
en_AG.utf8
en_AU
en_AU.iso88591
en_AU.utf8
en_BW
en_BW.iso88591
en_BW.utf8
en_CA
en_CA.iso88591
en_CA.utf8
en_DK
en_DK.iso88591
en_DK.iso885915
en_DK.utf8
en_GB
en_GB.iso88591
en_GB.iso885915
en_GB.utf8
en_HK
en_HK.iso88591
en_HK.utf8
en_IE
en_IE@euro
en_IE.iso88591
en_IE.iso885915@euro
en_IE.utf8
en_IN
en_IN.utf8
en_NG
en_NG.utf8
en_NZ
en_NZ.iso88591
en_NZ.utf8
en_PH
en_PH.iso88591
en_PH.utf8
en_SG
en_SG.iso88591
en_SG.utf8
en_US
en_US.iso88591
en_US.iso885915
en_US.utf8
en_ZA
en_ZA.iso88591
en_ZA.utf8
en_ZM
en_ZM.utf8
en_ZW
en_ZW.iso88591
en_ZW.utf8
eo
eo.iso88593
eo.utf8
es_AR
es_AR.iso88591
german
POSIX
ru_RU
ru_RU.cp1251
ru_RU.iso88595
ru_RU.koi8r
ru_RU.utf8
russian
ru_UA
ru_UA.koi8u
ru_UA.utf8
uk_UA
uk_UA.koi8u
uk_UA.utf8
>>> cat /etc/postgresql/9.1/main/postgresql.conf | grep -i locale
# - Locale and Formatting -
lc_messages = 'ru_UA.UTF-8' # locale for system error message
lc_monetary = 'ru_UA.UTF-8' # locale for monetary formatting
lc_numeric = 'ru_UA.UTF-8' # locale for number formatting
lc_time = 'ru_UA.UTF-8' # locale for time formatting
P.S. Debian Wheezy, Postgresql 9.1+134wheezy2.